Take a look at https://dnncommunity.org/forums/aft/1747.
Indeed, sites are coming back. One of my sites are back late yesterday afternoon All but one are back today, and intact. The one that isn't back I have hopes for.
Managed seems to be contacting account owners by email to let them know if sites have been recovered. They are using phone notification for bad news, at least in one case of which I am aware.
If you have the ability to log into your account's control panel, give it a try. If you can login and get to Pleask, that's a sign of good news. And, it may be that Plesk is availabe prior to DNN sites being responsive. This is a guess on my part.
There are other really good hosting companies. Google around and you are likely to find them. If you have or can get backups, you can rehost your DNN sites with one of them.