They can't devour your host brain
*claps dust off hands*
Of course excuses are just excuses but unless the game makes a point of telling us we're at risk of having our intelligence devoured, I won't make a point of it either. Maybe when we next encounter the Illithid faction our training wheels will be lamp-shaded...or have a hat put on it...it will be addressed I'm trying to say.
For the record I'd love an intro that makes us terrified of entering combat but we're not going to get that.