Yeah, the #hashtag is automatically linked to tags.hashtag. There is talk about how future proof this is in one of the issues.

I was wondering if we might one day be able to make # for tags and @ for people configurable, both to change the default characters (to avoid conflicts with e.g. Slack) and to allow even lazier linking to specific hierarchy nodes (e.g. I might define ^ as pointing to my microservice hierarchy in my work vault and save a whole lot of typing)