v12 aims to remove TS Shims. However, since no official alternative currently exists, users will still have to rely on shims when necessary.
Another alternative is adding genType output to core packages, such as Js and @rescript/core. This method may temporarily inflate the contents of the package and may add excessive migration burden in the future.
Since genType output is now a “runtime” dependency, there is some actual overhead, which is bad for users. It is also bad for maintainers because it requires an additional tsc build it.
Shims solve some use cases, so I may add documentation for that again.