The entire point of content management is organizing around content types... the fact we're 2 + years into this request, and there is no way to group by content type is mind boggling. But yet, sway is getting new features. ;)
2 years later... and no feedback. Ouch..
Yes, this is badly need. I have a Flow that creates events multiple times a day, and each time a personal calendar get a copy :( Sadly, the UI option (Send a meeting invite to group members) is NOT exposed in Flow or programmatically which forces us to NOT use groups.