Pan-Jewish changes to Halakha (orthodox law) are still theoretically possible. The last significant such occurrence was the ban on polygamy in Judaism about a millennium ago. It's just a question of how many rabbis, across how many streams of Judaism, would need to reach a consensus, in order for it to be reasonable to consider an amendment as "widely accepted".

In terms of changing the calendar rules, I doubt that there would be any chance of pan-Jewish consensus for quite a few more millennia, that is, not until the dates of major festivals get significantly more out of whack than they are now.

There is also the internet. Maybe everybody agrees and there is no objection to a correction?

It could be as easy as creating a Mastodon instance to find out.