I would say yes to tags. I would use categories for the high level content types, not for every product/version combination.
So there might be categories for:
Product AnnouncementsRelease NotesNews
And tags for:
- product:
1secure,auditor - version:
1secure-dpsm,release-minor, etc.
Discourse supports fairly structured tagging with tag groups, parent-child tag relationships, limiting one tag from a group, and category tag restrictions, so you can keep this from turning chaotic.
Then users can watch or watch-first-post tags, and you can set default tag notification levels.
If you have one release topic tagged with both product and new version
- category:
Release Notes - tags:
1secure,v10.8
Anyone watching 1secure gets it.
Anyone watching v10.8 also gets it.
Use the product tag only.
Does that help, or have I missed a nuance?