I think the "Use" in Life Cleric vs. "Cast" of Moon Sickle is the best explanation, although the reasoning extends beyond those two words in isolation. I've read several posts on this question across a few different forums, but haven't seen anyone point out the following distinction between the descriptions of Life Cleric and Moon Sickle: the extra hp given by Life Cleric is described explicitly in terms of the healed creature, when it is healed. For a spell that heals creature(s) after the initial casting, saying "use" the spell to heal instead of "cast" makes more linguistic sense, but I think the word choice matters less than the creature-centric description of Life Cleric. Namely, when the Life Cleric's spell restores hp to a creature, the creature gains 2+level more hp. This explains why it has to work with Goodberry - every time a berry is eaten by a creature, that creature gains hp, so the Life Cleric class feature is triggered and adds the bonus hp. And for good measure, the description of Goodberry dictates that you can only eat one at a time. So every single berry is necessarily a separate healing instance of a creature. The Sage Advice on this is right on. Same with Healing Spirit and Aura of Vitality.
Now look at the Moon Sickle description - it says when you cast a healing spell you can "roll a d4 and add the number rolled to the amount of hp restored" by the spell. No mention of a creature getting bonus hp - just the initial casting of the spell and the amount of hp it restores. Goodberry is a spell that restores 10 hp. Healing spirit is a spell that restores 1d6 hp a prescribed number of times. Aura of Vitality is similar, just with a higher ceiling on the hp restored by the spell. I think it is pretty clear that holding a Moon Sickle allows you roll a single d4 and add it to the total. If you roll a d4 for every goodberry - or a single d4 and add the result to every goodberry - then you are adding 10d4 to the hp restored by the spell, which is way beyond what the description of Moon Sickle says. I think a single d4 roll is the answer, although it does leave a question about how/when you apply it. To the first Goodberry, or to the first use of Healing Spirit? Does it make d4 extra Goodberries? (I have seen this regarded as a silly result, but I like it the best - it adds an extra d4 hp of healing in the same form as the other 10 hp that goodberry restores). I think the how/when is a DM call - personally I'd let the druid/ranger holding the Moon Sickle decide how/when they want to apply the extra d4.
(As a sidenote, I'm not a fan of the "goodberry is not a spell that restores hp" argument. That is like saying booming blade is not a spell that deals thunder damage at low levels - it is just a spell that sheathes someone in booming energy. Come on.)
Sage Advice is always optional. Within Sage Advice it says so.
It was one of Crawford's worst tweets and would make a 1st level spell totally unbalanced healing imo.
It still takes an action to eat a Goodberry, and foregoing your action for 4 hit points will rarely make much sense.
thats true, but life cleric and goodberry do mix, just not the moon sickle
I think the "Use" in Life Cleric vs. "Cast" of Moon Sickle is the best explanation, although the reasoning extends beyond those two words in isolation. I've read several posts on this question across a few different forums, but haven't seen anyone point out the following distinction between the descriptions of Life Cleric and Moon Sickle: the extra hp given by Life Cleric is described explicitly in terms of the healed creature, when it is healed. For a spell that heals creature(s) after the initial casting, saying "use" the spell to heal instead of "cast" makes more linguistic sense, but I think the word choice matters less than the creature-centric description of Life Cleric. Namely, when the Life Cleric's spell restores hp to a creature, the creature gains 2+level more hp. This explains why it has to work with Goodberry - every time a berry is eaten by a creature, that creature gains hp, so the Life Cleric class feature is triggered and adds the bonus hp. And for good measure, the description of Goodberry dictates that you can only eat one at a time. So every single berry is necessarily a separate healing instance of a creature. The Sage Advice on this is right on. Same with Healing Spirit and Aura of Vitality.
Now look at the Moon Sickle description - it says when you cast a healing spell you can "roll a d4 and add the number rolled to the amount of hp restored" by the spell. No mention of a creature getting bonus hp - just the initial casting of the spell and the amount of hp it restores. Goodberry is a spell that restores 10 hp. Healing spirit is a spell that restores 1d6 hp a prescribed number of times. Aura of Vitality is similar, just with a higher ceiling on the hp restored by the spell. I think it is pretty clear that holding a Moon Sickle allows you roll a single d4 and add it to the total. If you roll a d4 for every goodberry - or a single d4 and add the result to every goodberry - then you are adding 10d4 to the hp restored by the spell, which is way beyond what the description of Moon Sickle says. I think a single d4 roll is the answer, although it does leave a question about how/when you apply it. To the first Goodberry, or to the first use of Healing Spirit? Does it make d4 extra Goodberries? (I have seen this regarded as a silly result, but I like it the best - it adds an extra d4 hp of healing in the same form as the other 10 hp that goodberry restores). I think the how/when is a DM call - personally I'd let the druid/ranger holding the Moon Sickle decide how/when they want to apply the extra d4.
(As a sidenote, I'm not a fan of the "goodberry is not a spell that restores hp" argument. That is like saying booming blade is not a spell that deals thunder damage at low levels - it is just a spell that sheathes someone in booming energy. Come on.)
I would totally agree with your above statement.
I'd let the Moon Sickle do the d4 on the first berry created and the rest of the berries are minus any d4 from the sickle.