Perhaps each research area need a mastodon instance to provide a locus for discussion and sharing of new work? Organised nationally or trans-nationally.
Mastodon can already be a drop-in replacement for Twitter for many use cases. The biggest hurdle are, as ever, network effects. Not infrastructure, not features.
For me personally most of the people I care about already are on Mastodon. It was a smooth transition for me personally and I don’t miss a thing. All that needs to happen is for that to be also true for you and Mastodon is a drop in replacement.
The biggest issue I can see developing is a Gmail-ification of Mastodon (with a lot of people being on a single instance).
That would be a pity – but in terms of freedom e-mail is still pretty great.