Well, I can confirm that this is the case with a brand new account.

I created an account, picked "pets" as my interest. I was suggested several pet-related accounts to follow, and followed none.

I went to the home page and "for you" was populated about 80% from known right accounts and angry right-flavored screeds from people I didn't recognize.

The other 20% was just a smattering of random, normal stuff. None of it about pets.