That's a lot of questions. I'll answer each in turn.

Have things been improved with this new packaging/bundling of distributions?

I think so, but that's really for each person to decide for themselves. There's plusses and minusses with every tool. Right now the Platform is still in early days. I think it will only get more useful and appealing in the future

Can a user install directly from the CPAN if they so choose?

There's nothing that would prevent you from installing things from CPAN using the normal CPAN toolchain with a Perl we provide. If you were to mix CPAN modules with things we provide, it would eliminate most of the Platform's benefits. You wouldn't be able to easily replicate this project's environment elsewhere.

The one wrinkle is that we don't ship the compiler and toolchain that we use to build this stuff with the bits. So you'd need to have a compatible compiler, make, etc. On Linux this won't be a problem. On Windows our 5.32 build is using mingw, so it's probably not too hard to replicate that environment for yourself. When we have macOS working, that will use either GCC or Clang, so that is easy to replicate as well.

What's the support model?

The support model is similar to most SaaS services with a free tier. We offer free support on a best effort basis via a Community Forum. And of course, paid tiers have more support included.

In a year when a license runs out, are all of the environments going to be unusable, or without ability to add new distributions?

The Perl core and modules you install are simply licensed under the same license as the Perl core and those modules. If the Platform were to disappear, you could still use those bits, copy them, and redistribute them under those licenses. So in that sense the Platform and its tooling is just making using this more convenient. You're not required to use the Platform to use the bits you install.