Top level license file inconsistent with some file headers (some are LGPL 2.1 with link exception)

[MSoegtropIMC]

The top level license file of Merlin says it is MIT, but some files included in it say in their header that they are LGPL 2.1 with link exception, e.g. https://github.com/ocaml/merlin/blob/main/src/ocaml/parsing/ast_iterator.ml. Note that I don't think the LICENSE file referenced there describing the link exception exists in the source tree:

merlin % find . -iname LICENSE 
./LICENSE

This needs clarification / clean up.