@fchapoton This deprecation in #31545 is inconsistent. While InfiniteAbstractCombinatorialClass can indeed go (can be just removed now, as ~2 years passed since its deprecation), UnionCombinatorialClass and FilteredCombinatorialClass are used in CombinatorialClass - which is not formally deprecated (there is a comment there saying it is, but no deprecation notice).

Originally posted by @dimpase in #31545 (comment)