The thing where people use Mastodon content warning as a title is questionable. Once people are accustomed to ignoring a warning it's broken.
Armchair quarterbacking
Emergent/unexpected use of software features is to be expected, but I'd roll out a title mode for this pretty quickly in response - I suspect most people don't want to read/dismiss what people are writing as title (but it's fine if people want to write a title.)
Armchair quarterbacking
I'd like to understand more about why people apply CW vs. tagging. Maybe CW is appropriate as the opposite of tagging? - "this content is not meant for anyone to find, it embarasses me, it is the opposite of tagged/searchable?" (That is not how I'd like to see titled posts go down!)