The point I'm making is that this is already the de-facto thing. People on this email list do it, people in talking in irc and in forums do it. I don't think it has so much to do with markdown documents as it does with Slack, Discord, Teams, even google chat adopting that convention. All our fingers are getting trained to backticks everywhere *except* org documents. As those already have trained us to use this construction, it might be a good idea to just swallow the pill.
I don't think there's much of a slippery slope here. Most popular chat programs don't support making headings markdown-style for example, and even if they did I don't see many people attempting to use that.
Trying to enumerate syntax that I feel falls squarely in this category I come up with only a few
- lists with dashes, org supports that just fine
*bold text* with stars, again org already does this
`backtick code`, org doesn't handle this and actually uses the tilde as a delimeter which is extra jarring since its a strikethrough in many chat apps
That's really it. You could maybe also argue
> gt for quotation - that would be be nice as we're used to it from email as well, but I don't see people using it all that much
but that's really it as far as common usage right now. Sure that list might grow as different usages become common, but I would hope org is not against evolving in small and reasonable ways as the expectations of users shift.