I narrowly avoided the same issue, and I'm looking for answers.
I have no answer to this, butI came here today to find out the answer to whether my many WebAssist products would have issues with the update. I paused right over the "upgrade" button for half a minute, then I checked my email from WebAssist about it (nothing), then I came here and learned the bad news from Peter. Given WebAssist's track record and quality, I would have expected an email alert as to the issue. Now, I'm waiting for the news regarding an update / upgrade plan regarding my many recent years & legacy products. Your move, WebAssist!