This is certainly a growing trend which was first started amongst end-users themselves, and slowly we've seen a few news media outlets also following suite. So far, only a very few government agencies have actually followed. Coming to mind are also The Netherlands. What is attractive for many organisations and agencies on Mastodon, is that...
Find interesting people in those hashtags and follow them. Not everyone posts using hashtags everytime so you’re very likely missing on a lot of interesting content. Also, if your local feed (the one where you see posts from people on your own instance) is not of your interest you may want to migrate to another more specific or general, depending on your choice.
Thanks a lot, I’ll try that !