Not just syntax (though that would be important to cover too) but how the language is behind used as spearheaded by some of the newer frameworks like Hanami Web Framework | Devtalk (though I can’t remember exactly what they’re doing different now, but recall hearing some people say its a more modern approach).
Concurrency too - how will people be making the most of it using Ruby, what kind of concurrency model it is, etc.
Congrats on your thesis btw, it looks great!
We touch on some of this in our 2021 update 
I was going to start a thread about that but haven’t got around to it yet 