The change from openhab2 to openhab is mentioned in the release notes, but it doesn’t directly point out that this will be an issue for Samba. That’s tricky, because it could be an issue for lots of things that affect individual users. Also, I suspect that people who are upgrading now aren’t looking closely at release notes from 3.0.0, since it’s no longer the most recent version. I suppose it could have been mentioned in the breaking changes.
That aside, a post in the community won’t do much to help future upgraders. I’d instead suggest looking for the right spot(s) to add this to the documentation (I don’t know what those spots are), and then submitting the edit yourself. Otherwise, upgraders won’t find your useful tip until after they’ve gone through the same experience and come here looking for answers. 
There’s a great post that can help you get started with documentation, and once you do it a couple of times it’s easy.