I just switched to T-Mobile with my Pixel XL and apparently I'm 90 percent sure they have RCS support..I don't see it in the app though.. should I delete Android messenger and redownload it to see the option or am I uninformed about something?
T-Mobile's RCS support is limited to in-network messages sent using an Advanced Messaging capable app. Metro PCS had full network support for RCS as of the 2012 spec (they were the first in the U.S.) but further data since being acquired by T-Mobile isn't available in full detail. To me, that means it probably doesn't support the latest RCS standards network wide.