Where are you seeing that?
I may be mistaken, that's always a possibility.
But I suspect you saw that some of the powers were listed as "Passive Feature" and some were listed as "Class Action."
The "Class Action" just means that you have to activate the ability with an action, as opposed to the passive abilities.
Please point me to another source if you have one? In all the mix of information that's been coming out, it's possible I missed something. But again, this is what I currently think you're referring to.
Here is potential proof of this, the official BG3 twitter account(owned and ran by Larian), tweeted
this:
"Embrace your Illithid Powers as a druid and unlock the ability to Wild Shape into a displacer beast, tentacles and all. (aww, isn't it cute? 🐱 ) #OnlyInBaldursGate"
This appears to suggest what I was saying is correct...that "Class Actions" are indeed tied to your player class, and that the Displacer Beast transformation is indeed a druid only ability. The specifically add it is tied to the Wild Shape power of the Druids that other classes don't have and can't use.