Honda is well known as the leader for supplying parts for its legacy products. They are still producing many parts for all their bikes going way back. A quick check at Service Honda and their online system goes back to 1974 with a folder named ‘models with no year’ below that with numerous models listed.
My brother was able to order a carb kit for his vintage Honda Trail 90…..no problem.
I think Stock Honda is safe for quite a while yet….plus you can still get service manuals! :)