Are you asking if you post in communities do you still need to use the tags? Like for instance if you post in the Natural Medicine community should you still use the #naturalmedicine tag? I personally still do this but I think as long as you are posting in the appropriate community it's fine either way.

Posting in a community helps with building connections to other people who also share the same interests as you. When you post in niche communities the people there that are reading your content are already interested so it does help with getting support in that aspect.

However when it comes to OCD curation we nominate posts both written in and out of communities but we do encourage people to try to find communities that fit the subject they are writing about.

Hope this helps :)