Oh, interesting, it's the first time that I see a single update for the plugin. Up to now it was delivered with VBR.

Ah, ok, I should have read the whole KB…

“The Veeam Plug-In for Oracle RMAN package on this article is also included with the Veeam Backup & Replication 11a P20211211 installer ISO. It is provided here as a separate download for Veeam Backup & Replication deployments on the previous 11.x builds of Veeam Backup & Replication.”

So, it is as I said before and the plugin is part of VBR 11a P20211211.