Yep, that has been my concern as well. This has become common at Intel. A few years ago they even pulled all the existing updates for end-of-life products from their site.
I don't expect indefinite feature updates, but products should enter a maintenance phase after some predefined length of time and from then on receive bug fixes and security updates. I think most consumer cards from Nvidia and AMD receive about ~10 years of support in the way of driver updates.
One nice thing about Linux (or open source in general) is that the community can pick up the slack when the manufacturer no longer provides support, though that doesn't work so well with Nvidia.