It's actually working for me on my pixel 2. I swapped my sim back and forth between the pixel and a Huawei elate several times in a few mins and I think the system got confused and left it on when I put it in my pixel 2 and it's been working 2 months now. But i am afraid to take it out now for fear it may stop working.
It seems there is a completely artificial limit on non-cricket models. I don't understand why its disabled for any phone; if the phone supports VoLTE it will use it, if not, there is no downside to it being active on the provider side.