This will intend that you have not made a microsoft update in 5 year if I understand correctly , signature protection are based on very specific flaw of the software maybe check point improved that protection.You can always decide to take the risk and not update your software for more than 5 year , it is a possibility too.
Deactivating ips protecion should fit to your environment so you can decide to remove some server protection for software that are not in use into your organization , you should be able to do that for your client too.
Bottom line in my opinion as I said before if you don' t manage software update for more than 5 year or more don' t believe ips will save you but those are my two cents