There has been work going on replacing the usage of VirtualRESTService classes within our code bases like Math, Flow, Collection extensions etc.

Usage has significantly dropped and we can soft deprecate this class to notify code bases not maintained by WMF to migrate. We could do this migration if there is someone to review for those extensions like VEForAll, MathSearch etc.

This task is just to soft deprecate this class in 1.41

As expected, for WMF maintained/deployed repos, we have only VisualEditor and ContentTransform left: https://codesearch.wmcloud.org/deployed/?q=VirtualRESTService&files=&excludeFiles=&repos=, which is being migrated slowly Cc @daniel.