I'd be surprised, if this topic didn't come up in the past, but I haven't found any discussion of it. Any pointers would be highly appreciated.
The problem: Every new social network feels the necessity to invent a new set of potentially incompatible meta tags, that developers are supposed to put on their page.
Possible solution: Qualified meta tag names. Augment a name like
description with freely selectable strings. Possible variants:
<meta name="description.facebook"> <!-- CSS class name style -->
<meta name="facebook:description"> <!-- XML namespace style -->
<meta name="facebook.description"> <!-- Dublin Core style -->
<meta name="description facebook"> <!-- "favicon" style -->
Personally, I'd suggest the "CSS class name" style, since it'd trivially allow to qualify a meta tag for more than one vendor.
Example: Say your page has a long description, that all networks but Twitter and Mastodon should use. Then you can mark up this in this way:
<meta name="description" content="long and winding description">
<meta name="description.twitter.mastodon" content="short and sweet">