References to Watergate are ubiquitous (especially thanks to the angle journalists like to take on the current US president) and it was probably mentioned in history classes in school too at some point. I know it's supposed to be part of the curriculum in history classes in some German-speaking countries.
Granted it might not be familiar to someone from a non-western country though.
"I'll give you my Millard Fillmore PEZ Dispenser when you pry it from my cold, dead hands!" [3]
[1] https://louisianavoice.com/2015/07/02/taking-a-break-to-addr...
[1] https://www.cs.cmu.edu/~jbigham/pubs/pdfs/2019/twitter-alt-t...)
[2] https://help.twitter.com/en/using-twitter/picture-descriptio...
Either way, anything that makes Twitter a little less awful is nice to see.
Mastodon started in 2016, so it was a bit early. It added this feature in 2017: https://github.com/tootsuite/mastodon/commit/4ec1771165ab8dd...