The updates could be important in protecting the machine from outside influences. These are work computers, it isn't worth taking a risk for.Why do anything? As I understand it, Windows 10 will still continue to run on the old machine. It just that you won't get updates.
But I'm still running all the Lotus software from eons ago and even Quicken98 on W10
The only issue I see is if you get some new software package, it may not be compatible.