Now it's actually only a just shy of a four year version jump since v2.4.2 came out in mid June 2018 and v3.5.3 came out end of May 2022.
If another instance existed still live on v2.4.2 and updated to v3.5.3 back in around early July last year, just before I found all the mentioned oldest version record holders, then that would hold the record for the biggest version jump.
But I very much doubt that'd be so. And in regards of who can take that record away from Greenpeace?
Right now, the only two possible candidates able to take it is vipgirlfriend and pritter. Not even catdon.life would be able to take the record away if it updated right now directly to v4.0.2.. as there's 5 versions + 5 release candidates between v2.4.2 and v2.5.2.. meanwhile there's 2 versions + 2 backports + 4 release candidates between v3.5.3 and v4.0.2.
So despite that v2.5.2 came out in October 2018, and v4.0.2 came out in November 2022, which is just over 4 years.. that jump would leave catdon 2 releases short of Greanpeace's jump.
If catdon wants to be on par with Greenpeace's record, they'll have to wait out til version v4.0.4, or longer if they want to top Greenpeace's record. But then the question might be could they even do it? Is there a reason that Greenpeace jumped to v3.5.3 and not directly to v4.0.2 besides the big ui change.. something of which they had a huge ui change regardless with how Mastodon was back in 2018.