The user.tokens module is an internal optimisation to avoid one extra API roundtrip for built-in ajax actions such as "Ajax watchstar" and submitting edits to the API for e.g. VisualEditor and such.

The tokens should be retrieved via mw.Api#getToken which already supports all other token types. There are no plans to expand the set of preloaded token types as there is no performance reason to do so (yet).

Note that since 2014, most token types (such as move, edit, delete etc.) have been deprecated in favour of a single csrf token type, which should already significantly reduce the number of cases where mw.Api#getToken would actually need to fetch a token.