Google’s Pixel handsets have previously been available from Verizon only in the United States but the company is switching things up with the Pixel 3a and Pixel 3a XL. The new affordable handsets will be available from other carriers as well, including T-Mobile, and if you get one on Magenta just keep in mind that the carrier won’t be supporting RCS on these devices.
RCS is the modern version of text messaging with additional functionality such as read receipts and the ability to transfer files. It’s supported on most modern Android smartphones but carrier support has been lacking. That’s the main reason why you won’t find support for RCS on T-Mobile’s Pixel 3a and Pixel 3a XL.
The previous Pixel handsets were not sold by T-Mobile but unlocked versions could be used on the carrier. It would make sense if those units didn’t have RCS support. However, T-Mobile is now selling the latest Pixel devices, and yet there’s no support for RCS. When asked by a follower about the support, the official T-Mobile Help Twitter account confirmed that the “new Pixel devices won’t support RCS messaging.”
Google’s Messages app does have RCS support and it works very well on carriers like Verizon but not T-Mobile which has only rolled out support for some major devices so far, devices like the Samsung Galaxy Note 8 and 9, Galaxy S8 series, and the OnePlus 6T.