Depends on your tooling. I can't update yet due to ESLint package dependency mismatches. I'll have to wait for all the ESLint plugins to update. There may also be new failures in your code from the v6 to v7 update. I had only a very minor one though in my initial test.

It depends, but for larger projects, you might have tooling for TypeScript that relies on its API, which isn't available in TS 7.0.

If you’re continuing to use the previous version in CI, there’s no reason to not use this locally. It’s a tremendous speed upgrade.