If you can still edit your message on the older thread/page, you should link to this discussion (or post a new message). That way, the circle of life will be complete haha
I’m kidding of course (you should still do it if you can/want) ;)
It's very annoying. I think the time limit should be on the order of months rather than hours.
I tend to think that online discussions are better when people can edit their posts, correcting mistakes, adding context or information, or even changing their position in light of new evidence or convincing arguments.