Yes, there was a notice in the app, but Samsung abuses those notes to spam us with all kinds of irrelevant junk. I have been trained to ignore the flag showing that I have notices because 99% of the time there is no useful information.
I have a lot of sympathy for folks who were caught unaware when all Groovy Smart Apps were shutdown.
Samsung has in their servers an exact list of every device that every user of the SmartThings app has connected along with the DTH in use plus every Smart App in use. And an email address to reach everyone. As a former software developer I won’t minimize the effort it would have taken to generate a mass emailing that included a user-specific list of probable at-risk devices and apps. But it certainly seems to me it would have been possible. And it would have greatly reduced the ill will that has been generated.
Edit: I obviously didn’t read @JDRoberts last post before writing this. If I had, I would have just said: “Yes! What he said!”