Nobody but Ruger knows for sure. If you're the owner of a Gen I RAR, strongly suggest that you obtain spare parts for your particular rifle while it is still possible and easy to do so. I understand that doing so, in the case of "factory-fitted" parts will require sending the rifle back to Ruger, as well as removing all user made mods/equipment. That's how Ruger is, and I kinda understand.
OTOH, if there's anything "bugging" you about your Gen I RAR, now's the time to get it fixed while parts/expertise are still available. Spare parts, particularly "fitted" spare parts, are like money in the bank; they grow "interest"/value as time goes by, as long as receipt is kept. Selling off a discontinued rifle, as long as it has spare parts, is a LOT easier than selling off an "orphan" without parts/factory support.
Long ago, I sent my Mini-14 back to Ruger for purchase/"fitting" of some spare parts. I mentioned, in passing, that the Mini was not as accurate as I'd hoped. Ruger fitted and head spaced a new bolt--on their dime. Mini shot a lot better afterwards. A lot better.
Ruger certainly has discontinued some firearms, and Ruger parts/service support for them ranges from non-existent to "Limited", which often means critical "wear parts" are sold-out. "Limited" eventually changes to "non-existent", if the parts are not common to subsequent firearms.
For that matter, any firearms owner who has not yet accumulated a stash of frequently replaced parts for their firearm is guilty of neglect. I have NO doubt that the Antis would love to restrict/eliminate spare parts for firearms.