Hey Cindering,
Recently, we have been working closely with Xbox to ensure that the Roblox platform is meeting Xbox Requirements. This change was made yesterday, and we are still preparing communication to announce to the wider community. We will also be making changes to the Developer Hub Xbox page to reflect this information.
As your players discovered this means that text chat is no longer available. You did mention in this post that there are other features that accept custom input that are affected by this change, would you mind giving me additional information?
EDIT: We just made an announcement regarding this. Updates to the Featured Game Guidelines Page