Absolutely.
There is no way I could work with a therapist who couldn't say this. I would never ever be able to be genuinely vulnerable with them.

Edit:
Actually, I need to add a stipulation...
I could never work with a therapist who I didn't KNOW cared about me. C has definitely told me he cares about me, but he's not about to put it on repeat - he wants me to trust his actions & what I know of him over anything he SAYS. It's a big contention point in our therapy, because I have often asked him to SAY things that he wouldn't say but didn't mean they weren't true.

But "I care about you" isn't one of those things.

I can certainly imagine a T having a boundary around saying "I love you," but "I care about you" seems an odd verbal boundary to have.