I see quite a lot of #Science posts expressing concern if The Public will follow their authors' #TwitterMigration over on here.

Here's the thing: they don't even have to. Every #Mastodon account has an #RSS feed. For example, here's mine:
https://mstdn.social/@rysiek.rss

Every hashtag has an RSS feed as well (as seen from a given instance), for example:
https://mstdn.social/tags/Science.rss

Your audiences can follow you without ever setting up an account on fedi, with any RSS reader.