I'll start, I'd rather have YYMMDD_xx_title-words.md, where xx are the principal engineer's initials. It'll handle the merge/pull issue, and also show at a glance who was making architectural decisions (and if they were making too many at once), though I would love to hear how something like this has blown up in the past.
What I don't like in your proposal are initials - since 2020 I worked in the environments where all folks were invited in making architectural decisions (that's the way I always try to push as an architect), therefore it would make no sense to add any initials :)
I guess what I'm solving for is trying to tag a specific person or group with why a decision got made, which... if there was an easy way to do that, politics would be a lot cleaner. Removing that, and just adding many-to-one tags for authors in-document, seems like it'll get to most of the desired requirement.