I have been asking smartthings staff for over two years What would happen to virtual switches created under the old architecture. And each time I have been told that “we’re looking into it.” In August 22 there was an official announcement that there would be a future announcement about this device class, but it never happened.
And now, today, again, without any announcement or documentation, they just don’t work.
There is no scale that can measure the depth of exasperation I feel at the way this has been handled. Why not just tell us three months ago or six months ago or two years ago that these devices would all have to be re-created under the new architecture? And give us some warning about when they would be turned off? Why make every day a minefield for those of us who depend on home automation to be more than just a gimmick? 
And I’m not the only one who’s asked the question about automatic migration of virtual devices. But I don’t think anyone’s ever gotten an answer other than “we’re looking into it.“ So frustrating. 
Note that the following question was posted almost a year ago.