Why the package haskell-platform does not follow the proper version number?

The package haskell-platform is a metapackage providing tools for developing in Haskell. It is [self-distributed](https://www.haskell.org/platform/prior.html) with a versioning system using a version number, the release year and month. It is as well distributed on different distributions such as [Debian](https://packages.debian.org/en/buster/haskell-platform) . I could not gather how the Debian package number was made, since the latest on Buster is labeled as 2014.2.0.0.debian8, which comes, e.g. with ghc >= 8.4.3. The problem is this ghc version is from 2018. I was wondering if it was a deliberate choice from the packaging team or mislabeled from the website/documentation, since it seems that the packages provided by this metapackage. I might have missed something, but I do not see the consistency here.