Follow-up from "Remove allowlist autopopulation migration tooling"

The following discussion from !214627 (merged) should be addressed:

• @jmallissery started a discussion: (+7 comments)

  @dbiryukov I have a question if this MR in which we remove a feature is a breaking change ? As per docs we are not allowed to make any breaking change without following the breaking changes workflow. Correct?

  I understand that the allowlist auto-population is a temporary migration feature, but I see that we have NOT marked the feature as experimental in our docs

  So, direct removal of the feature as well as the GQL API fields without deprecating it first feels like it is violating our breaking change policy. WDYT ?

  CC @jocelynjane

There are deprecated fields that need to be marked as deprecated.

cc @ken.mcdonald