Anything is possible but I suspect the Primal team made the design decision to use a cache for their app so probably won’t change it.
I think it could make sense to implement a fail back to local processing of notes directly from the relays in the case that the cache is unreadable. At least that way the app would keep functioning if there was a cache outage, although that would likely be with a more limited set of features than with the cache.
I could see it being a design decision since that probably simplifies a lot of client code and they're building several clients.
But given that they're trying to make a profit somehow that seems like exactly the kind of thing you'd try to charge for.
Primal is optimizing for new users so that they have to configure as little as possible for the app to just work. The caching relay set as the ONLY relay the client is reading from fits right into this objective. Users don't have to wonder why they don't see notes on Primal that are visible elsewhere, because chances are the caching relay has pulled them in from other relays. Users don't have to go and make sure they are reading from the relays that their friend who told them about Nostr is writing to for the same reason.
That being the case, I don't think they would ever make the caching relay an optional service that is only available to premium subscribers. It is too fundamental to their user-friendly UX.
Yes nostr:npub16c0nh3dnadzqpm76uctf5hqhe2lny344zsmpm6feee9p5rdxaa9q586nvr confirmed they intend on adding a fallback
note1kdqwf24qu3cur6gsmynmqy2tzu9z4mnl8ymnwgrrgequssurl85sj9y498
