Switching Carriers? (XS Max)
I'm on the Apple iPhone Upgrade Program. I am currently with AT&T, but I've wanted to switch to Verizon for a while now. When I preordered my XS Max, there was no option to change carriers (though the iPhone Upgrade Program webpage does explicitly state that "if you ever decide to switch carriers after you activate your iPhone with AT&T, Sprint, T-Mobile, or Verizon, you can easily do that, too."
With my old iPhone X, I was told I couldn't switch from AT&T to Verizon, because one used GSM and the other CDMA. That particular asterisk is no longer mentioned on the iPhone Upgrade Program page, though.
My question is: am I going to have any issues swapping my XS Max from AT&T to Verizon, once I receive the new SIM card? When the iPhone XS Max is purchased via the iPhone Upgrade Program, is it carrier locked?
Note: I'm only interested in responses from those who know the answer with absolute certainty, based on the new XS and XS Max models — not supposition based on older models.
Thank you
iPhone XS Max