I managed to get some information on why meek-google got suspended on App Engine. There was a botnet that used Tor and the public meek instance for command communication. They shut it down for that reason. I still haven't gotten any kind of official communication from Google Cloud Platform.
I wrote a guide on how people can set up their own personal instance. https://lists.torproject.org/pipermail/tor-talk/2016-June/041699.html I figure the botnet risk is far less this way, without a single central service to freeload off of. Though of course far fewer people will be able to follow these steps than were able to use a default configuration.
Because I can't see just setting up a new account under the circumstances, I'm planning to ask the Tor Browser devs to remove the non-functional meek-google option.