Microsoft is rolling out a new update to the Xbox app on mobile devices, and it brings an improved experience for the messaging aspect of the app. The new experience was first teased when Microsoft announced that it would be removing support for messaging in the Xbox app for Windows 10 in favor of an improved experience that's expected to come through the Game Bar overlay.
Both the Android and iOS versions of the app have been updated, and though the changelogs on the respective app stores are different, they seem to include the same changes, according to Mehedi Hassan of Thurrott.com. The new messaging experience should be faster and more performant, and there have been improvements made to group chats.
There's also now a section for message requests, which is where you'll have your messages from people you don't know. This is pretty similar to experiences on platforms like Facebook, and it should help you keep spam from disrupting your conversations.