this is a completely different scenario than what has been talked about for these NIPs.

here the data probably does not hold any value to the point where people would broadcast the events, and nip63 doesnt apply, only nip70. in that case it makes sense, but the user needs to know that they could be rug pulled anytime by that google drive and dropbox, if they were to not care about the tag anymore.

it would only be perfect in a scenario where the user owns both relays.

so if that user wants peace of mind, i wouldn't recommend going with nostr. it unfortunately isn't a solution in every scenario.

you know better than i do how nostr is, among a few other things, a solution to censorship, definitely not a solution to everything.