I'd like to see a campaign set in a somewhat grittier version of Planescape's Sigil where stuff like this forms the basic conflict. You not trying to kill the D&D bestiary, you're trying to figure out to coexist with them in a planar metropolis.Still evil because they're now sentient.
Makes human-illithid relations better. But I think it has to be certain humanoids not any. At least in other editions.
As for eating it depends on the species/race and options they have. If a race has to eAt humans idk if that's evil or not if they have the choice to eat humans or whatever it's a bit different.
That giant ant? Humans just another source of protein. Jon evil illithids is going to struggle a lot.