A bit of Googling landed me here:
https://groups.google.com/forum/#!msg/racket-users/-x_M5wIht...From there:
Phase 1: Brainstorming (months)
Phase 2: Iterative Design (years)
Phase 3: Conversion (months or years)
Phase 4: Transition (years)
I am a nobody in front of people like Matthew Flatt, but this feels like Seconds Systems Effect taken to its extreme definition: https://en.wikipedia.org/wiki/Second-system_effect
Plus as a former Perl programmer having watched Perl 5 lost almost everything, chasing a never to have come to reality Perl 6. I can say, given all this, the future of Racket as a language, for its core uses and users is pretty much dead in the years to come. Like dead totally. Racket doesn't even have as much the share of dev mind share or a resource like CPAN at its disposal. Languages like Racket will fade away into oblivion a lot more quickly.
It can be hard to see this in all the enthusiasm in the early stages of the project. But when you embark on multi year project journeys. People's priorities change, people get into health crises, lose jobs, move on to better projects, recessions happen. Core teams that started these projects change so much, newer one's pretty much give up and see no point in it after a while. Many people prefer a perfectly working tool improved over time, than a pie-in-the-sky idea that will never come to see the light of the day. While all this is happening, your existing language, libraries, dev mindshare, tooling suffers. Merely supporting small time fixes means nothing, because no one likes to use a tooling in hospice care. Your core dedicated set of users, who did most of the evangelism for your cause move on to newer tools and languages, for the obvious reasons that they don't see their future with existing tool they like, the newer one is taking for ever and isn't even the same goodness as the current one. Once you lose those users, the newer users you wish to attract from the crowd of Java and Python programmers won't even bother to try, why should they? They have something proven to work in production with tooling, libraries, books, and production success stories for decades.
That is when you realize you lost both your old and new language.
Racket was awesome for what it was. An awesome lisp, a top successor for Common Lisp and a playground for experiments and initiating people into Lisp.
It's not late. Probably it's time to stop right now.