Based on this Sage Advice  the feature create a weapon out of nothing, if that clears up any confusion whatsoever.

If a Warlock uses Pact of the Blade to bond with a magic weapon, does that weapon have to be a Melee weapon, and can the Warlock change the weapon’s form?

The Warlock’s Pact of the Blade feature lets you create a Melee weapon out of nothing. Whenever you do so, you determine the weapon’s form, choosing from the Melee weapon options in the Weapons table in the Player’s Handbook. For example, you can create a Greataxe, and then use the feature again to create a Javelin, which causes the Greataxe to disappear.

You can also use Pact of the Blade to bond with a magic weapon, turning it into your pact weapon. This magic weapon doesn’t have to be a Melee weapon, so you could use the feature on a +1 Longbow, for instance. However, you can’t change the form of a magic weapon using this feature. For example, if you bond with a Dagger of Venom, you can’t transform it into a Maul; it’s always a Dagger.

The feature allows the conjuring forth of a Melee weapon, yet we allow more versatility when it comes to magic weapons. We didn’t want a narrow focus in this feature to make a Warlock unhappy when a variety of magic weapons appear in a campaign. Does this versatility extend outside the melee theme of the feature? It sure does, but we’re willing to occasionally bend a design concept if doing so is likely to increase a player’s happiness.

And realistically, there's no reason why a bow should be locked out.  There are compelling reasons to want a bow, not the least of which is smite/prone at range.

Quote from crzyhawk >>

And realistically, there's no reason why a bow should be locked out.  There are compelling reasons to want a bow, not the least of which is smite/prone at range.

 Which type of bow, though? While a Short bow is defined as a Simple Ranged Weapon, a Long bow is defined as a Martial Ranged Weapon. Pact of the Blade can conjure a Short bow (a Simple weapon), while since a Long bow is a Martial Ranged Weapon, it can NOT be conjured because Pact of the Blade can only conjure Simple or Martial Melee weapons. It is a bit crazy but that is what the 2024 PHB says.

A shortbow cannot be conjured because the PBH states:

"Pact of the Blade

As a Bonus Action, you can conjure a pact weapon in your hand—a Simple or Martial Melee weapon of your choice with which you bond—or create a bond with a magic weapon you touch; you can’t bond with a magic weapon if someone else is attuned to it or another Warlock is bonded with it. Until the bond ends, you have proficiency with the weapon, and you can use it as a Spellcasting Focus."

Quote from Benturaq >>

A shortbow cannot be conjured because the PBH states:

"Pact of the Blade

As a Bonus Action, you can conjure a pact weapon in your hand—a Simple or Martial Melee weapon of your choice with which you bond—or create a bond with a magic weapon you touch; you can’t bond with a magic weapon if someone else is attuned to it or another Warlock is bonded with it. Until the bond ends, you have proficiency with the weapon, and you can use it as a Spellcasting Focus."

 I had thought that the wording of 'Simple' included 'Simple Melee and Simple Ranged' and that 'Melee' was restricted to 'Martial Melee'. 

Once again, the inclusion of a couple extra words would have greatly helped.

A magic bow can be your Pact Weapon though.

Yes, you can do that, however there are solid reasons to go with a physical bow instead.  You can't ever eldritch smite, with eldritch blast.  Being unable to conjure the bow isn't a problem per se, it's that by RAW, you can't bond a normal non magical bow as your pact weapon, do to pact weapon things without using a work around.  Having to wait until you get a magic bow or get someone to cast magic weapon on a bow for you to bond with in a word, sucks.