But they could order them to give them access to administer their servers, with acts of sabotage being punishable. There's no reason you should assume that the people running RiseUp right now are the same people that ran it a week ago.

Even if you shut down immediately (more on that in a moment), you can't wipe your storage and The State can still look through that

And if it is an ongoing investigation, shutting down immediately may be very difficult. Unless you can make a compelling case that you were already doing so for whatever reason, it is a very clear textbook case of obstruction of justice/interfering with an ongoing investigation.