The "you need to write in a more professional business oriented way" is something that a lot of people are having difficulty with. Yes, this needs to be addressed earlier in someone's education more forcefully - but the SMSification of long form text started a while ago.
With that said, the "Ok, you need to write long form with correct grammar when sending an email that a director or VP is CC'ed on". It used to be Grammarly as the "install this and have it fix up your grammar and tone" ( https://web.archive.org/web/20191104093353/https://www.gramm... GPT-1 timeframe there). However, LLMs of today seem to be more accessible than Grammarly but it largely does the same thing - fix up and refine tone.
What I don't see from back then is people decrying Grammarly saying that it's making everything sound the same.
I'm also not sure if I would prefer the pre-fixup emails to what is produced by an LLM unless sending coworkers to remedial writing classes is something that is acceptable.