Surprised to hear this as none of our Enterprise plugins had a change in licensing (i.e. going from free to paid, or shifting within paid tiers) as far as I am aware. Would love to dig into this further.
If you're up for it, feel free to send me a note at divy.goel@grafana.com or let me know how best to reach you!
https://grafana.com/blog/2020/07/22/introducing-the-new-and-...
As this is not how we (try to) operate, I also had a look.
From what I could find, it seems the account you are referring to is a very early Cloud account. For reasons I don't know and which might be lost to history, your account had an old and non-standard license attached to. From the viewpoint of today, the license itself seems broken.
To be clear, that is neither your fault nor do I believe you could have caught it even if you looked. While there was no change in the licensing requirements on the plugin, an upgrade to a significant rewrite of the plugin "fixed" the problem of accepting a broken license. That "fix" meant the plugin stopped working.
Again, this is not your fault. But it was not a deliberate action by Grafana Labs nor caught by our testing, either.
I believe your company is in contact with David Dorman, our Head of Self-Service, about this. If you'd like me to ask him to follow up with you directly as well, please let me know how to best contact you.