twinned spell's description says something about using SP to effectively increase the spells lvl (if its a spell like charm person) instead of using SP to to target an extra creature

the old description 

Twinned Spell

When you cast a spell that targets only one creature and doesn’t have a range of self, you can spend a number of sorcery points equal to the spell’s level to target a second creature in range with the same spell (1 sorcery point if the spell is a cantrip).

To be eligible, a spell must be incapable of targeting more than one creature at the spell’s current level. For example, magic missile and scorching ray aren’t eligible, but ray of frost and chromatic orb are.

the new description 

Twinned Spell

Cost: 1 Sorcery Point

When you cast a spell, such as Charm Person, that can be cast with a higher-level spell slot to target an additional creature, you can spend 1 Sorcery Point to increase the spell’s effective level by 1.

Not wrong.

2024 is a rewrite. Things are changed for clarity or rebalancing. 

The change to Twinned Spell is intentional so there are no errors here.