This issue is related to how Xbox live is communicating with IOS devices. Minecraft works fine on IOS when not signed into Xbox live. My older son, who is playing bedrock version (same as version on IOS device)- but on a windows computer, is able to load, sign into Xbox live, and play servers with no issues.
Did Mojang issue a hotfix to IOS in the last 24 hours that is causing issues between IOS Xbox live accounts?
Mod violine- what was posted on Twitter has nothing to do with this issue. Twitter support was referring to purchased content.