MeniPorat , I'm not working on Microsoft and have no idea which decision they make before such decisions are announced. That's better to discuss with AFE team here https://github.com/microsoft/advanced-formula-environment/issues. At least what they declare hidden sheets won't be supported in future.
GitHub is quite popular and quite powerful platform, but it's oriented on software developers. Perhaps that's why export to GitHub was excluded from this version. Friendly or not that depends. As with Visual Studio - if you run it first time to do simple task, you lost in bunch of other options it provides. But for people who use it on daily basis it's friendly since due to this bunch of options and they know the logic how to find and select them.
Again, current AFE is just concept. More feedback we give the better future product will be.