Companies these days focus on planned obsolescence. They do not want people to keep the cars forever and don’t want to maintain those cars. We just need to accept that.
Do we? I think you'll find that if you have a decades-old Porsche, or Ferrari, or Jaguar — even a rare one — those companies will generally take care of you. They may have to fabricate parts (some of them can be 3D printed now), or they may contract out some work to outside specialists, and it's definitely not cheap, but there's always a way. That's the part of the market the Roadster exists in, and we should expect Tesla to do the same.
It shouldn't be a huge burden on them. Tesla have only produced one rare and exotic model, not dozens. The Roadster is it. They can do this. I recall Elon once said that Tesla doesn't make slow cars. He's also bragged about how long their cars can last. I don't think it's much of a leap to expect that Tesla not make disposable cars either.
I should also say, I haven't seen any real evidence of flagging support from Tesla yet. The worst situation I've had was the failure of my PEM, and it did take a few weeks to source the replacement (not as long as I'd feared), and it was expensive, but they got one. And you know, getting parts in a timely manner has sometimes been an issue for the S, X and 3 as well. Don't read too much into it.
Longer term, I expect most of these cars will end up collected and conserved more, driven less. Personally, I'm a driver not a collector, and I don't really see keeping my R1 Roadster for long after the R2 arrives. It's been a fantastic car, and for now there's still nothing else like it, but inevitably its heyday will pass.
