I saw this shared recently. The site presents nicely, and I agree there's a gap there. As a university professor, the story of my students' learning has pretty much been; Scratch, some Python, and then they pick up whatever early-college curriculum is. There's a strong preference for scripting languages like Python and JavaScript.

When you say "what teenagers should do after learning Scratch," what do you mean exactly? Should do to what end? How would Easel present as "the clear thing" they should do? I suppose Scratch wasn't really chosen by these young people; it is obviously simple, and has the prestige of MIT. Schools followed suit.

You're in a different situation, where you have to meet this market in the open. When I visit your site, I am met with code. It's not apparently simple, and a beginner wouldn't be able to distinguish it from any other games programming framework. I think it's actually scarier-seeming to a beginner than something like Godot's scene editor, where you can just drag images from your disk into a prototype-view of your game-scene.

I hope my plainness in stating this isn't taken as an insult. You've got so much work there, and the site is impressive. I also care about this topic, age-range and the learning process, so I'm trying to be helpful with my perspective.