Yes it sure is impressive
No shared masternodes wont be a thing...for now at least.
I think it was a security thing. The team values its community members safety very highly.
You could try join the discord and ask the devs in charge of the cloud for a clear answer.

Qtum will be the next coin added for staking on the cloud and then last of the four will be decred.
How long that gonna take, i have no clue.
I know getting other coins masternodes setup to run with MNaaS has a high priority right now and alot of
work is therefor put into this area. So this could delay the staking area a bit i think.