So a application that wants to filter will categorize their services privately and then write custom filtering logic, but will not just categorize their services publicly? That is nonsense.

And your point about fail open versus closed also makes no sense since if there are zero repercussions to not writing filtering logic then nobody would even bother. If there is liability, then obviously everybody will fail closed and every application developer needs to evaluate and change their application to only allow acceptable usage. This is much harder if they have to write custom filtering logic instead of just publishing their data categorization.