For practical purposes, it is always very useful to have your notes and tasks in one place. So I would like to manage my tasks in Joplin. It would be very useful if we could associate due dates with natural language.
i add a task today #work
is interpreted as
i add a task with a reminder for today and a tag "work"
I don't use Joplin for my todo's, but as a Todoist user I can tell how useful such a feature would be. But for Joplin this might be too niche? This can also become very complex quickly if you have to support different languages, date formats, etc..
However, I think all the pieces are there for a plugin that supports your specific use case (English?). For parsing the input you might want to look into GitHub - peggyjs/peggy: Peggy: Parser generator for JavaScript. It's easy to pick up and has powerful transform features.