This is one of the most requested features in 5e in general. Luckily in 5.5e (not BG3) they are planning to make the warlock work with any mental stat.
Now that I think about it, we saw today some screen of the the blade pact the description talks about "your spellcasting stat", not "CHA". It might be just wording though.
Anyways, Eldritch knight and Arcane Trickster, subclasses of fighter and rogue, are INT caster's too.
Odd to do that with warlock of all classes, given the idea that charisma would be a very useful thing in coaxing an otherworldly being into a pact. If I were picking a class to make work with any stat, it would be sorcerer, which works on the premise of innate ability.
In fact, everything is not so clear. The power of the sorcerer is concentrated in himself, so he develops his own personality in order to reveal his own potential. However, the arcane heritage of the sorcerer exists in the pathfinder and its main characteristic is intelligence.
At the same time, the warlock must be smart enough, firstly, to make contact with higher powers, and secondly, not to lose his soul immediately at the time of the conclusion of the contract. The current system allows the warlock to have 8 intellect and 8 wisdom. That is, he even read the contract with difficulty. Of course, this is not so important if the higher power needs more than just the soul.
