Hi. "Unsupported" is a term used by the company that wrote the software, that happens to be over 10 years old.
If You've done the updates that they released on a fairly regular, or at a least a fairly recent basis, then You shouldn't have any issues with the software running on Your system(s) at this point.
From there it's all about knowing how to use the software, which - after over 10 years of being released, is pretty much handled by all the Youtube videos & forums websites anyway by now.
So no, You don't need to upgrade, as long as it still does what You use it for, but I WOULD be sure I saved as many of the update patches I could still recover from the system just in case it ever needs a re-install from the original disc(s).