you need 13 in some attributes to be allowed to... so as a example if you want to multi cleric and mage, you need 13 wis and 13 int...
True, that would be a limit by the rules. But let's say you spread out your stats as much as possible, I wonder how many classes they will allow you.
I also wonder how warlock spells will work with other classes (since they recover on a short rest). Will you be able to cast other classes spells with warlock slots? Or use warlock slots to smite? Hmm
I'm just wondering if there will be any Larianbrew on their end - they really didn't go much into multiclass.