Great question! It would be nice to hear back from Twitch staff. Last August I posted a question about a feature from v5 that is missing in Helix, and never got a reply. I even included links to two other posts about the same missing feature, neither of which were actually resolved.
It’s frustrating when you take the time to study the documentation, learn the ins and outs of both the old and new APIs, are then urged to migrate to the new API, ask detailed questions seeking guidance about missing functionality, only to be ignored. FeelsBadMan
v5 (URLs with kraken in them) has been deprecated and will eventually be turned off in favor of the new API (URLs with helix in them). It’s true that we haven’t discussed in detail what else is going into the new API before v5 is given a shutdown date. In the next few weeks, we are gathering feedback on some of these endpoints in a closed beta and will be communicating more about them afterwards.
In v5 Migration Guide | Twitch Developers, " Authentication Scopes", it is not clear if the kraken scopes will continue to work long after migrating to helix. Can we assume that our app can keep passing kraken scopes and then helix will keep auto-mapping those scopes into helix?
You should not keep using Kraken scopes. Existing tokens with Kraken scopes may work depending on if the migration docs include that scope having a Helix equivalent, but you should expect the Kraken scopes to no longer work for new tokens in the future.