https://tools.wmflabs.org/toolhub was where we were publishing the initial versions of the toolinfo schema. In those early versions, we used identifiers like https://tools.wmflabs.org/toolhub/schema/1.1.1 which we intended to be usable as a URI to retrieve the specification. It looks like https://tools.wmflabs.org/toolhub/schema/1.2.0-draft01 was the last specification published there on 2020-09-15. Later we began using https://gerrit.wikimedia.org/r/plugins/gitiles/wikimedia/toolhub/+/refs/heads/main/jsonschema/toolinfo as the git source tree location for schemas which ends up exposing them to the internet via URLs like https://toolhub.wikimedia.org/static/jsonschema/toolinfo/1.2.2.json.

The data here looks pretty stale. I doubt there is any significant community usage of these old URIs/URLs to access the toolinfo schemas. The canonical public docs on the schema point to https://gerrit.wikimedia.org/r/plugins/gitiles/wikimedia/toolhub/+/refs/heads/main/jsonschema/toolinfo as a place where they can be viewed.

Retiring the hosted schemas and making the tool into a redirector for folks who badly typo wikimedia.org as toolforge.org seems like an ok thing to do. Or at least I can't think of a good reason that it should not be done at the moment.