Stumbled on this thread when I could not find some parts on the Lionel site. One thing this hobby has is a lot of smart people. I think one way or another trains will keep rolling. Even auto MFgs stop making parts at some point but look at all the 10-20 yr old cars in daily use. I’ll stand by to stand by now
You can't use cars as an example, they make millions of cars a year and cars production runs are measured in easily 5 years or more. Likewise, after 7 years third party people can make replacement parts. Unless you have some exotic car, getting parts for a 20 year old camry or whatever is no big deal.
Trains are low volume and they don't stockpile a lot of parts, pure and simple. I understand people's concerns, you spend a lot on these products and basically there is little support to start with and down the road, you can be left adrift with a 2000 dollar paper weight. I don't know the long term reliability of these engines but in a sense what Lionel is doing is what appliance makers do, you buy a washer, a board fails 6 years after you bought it, and you can't fix it. Thing is a washer at least is 1 item, but you are paying washer prices on a toy train engine, but Lionel et al pretend like it is the same thing.
That said, this is not new. I bought used many years ago a (conventional) Erie Lackawanna MU set. It works, but certain features don't work right. I asked about fixing it with my local guy, he said you couldn't get boards for that unit after a couple of years after they sold them new(this was like 6 years after they were made). Heck, people have said it is hard to get parts for late model legacy and other engines, too. Do I think this is good? No, just saying from all the complaints on here over the years you are playing a form of russian roulette with these engines and how long they work. I would wish that Lionel and MTH would allow third parties to make parts once they decide not to stock them, it would benefit them in the long run...which is likely part of the problem, more than likely people running the show only care about the next earnings sheet. Thing is, if worries about future support stop people from buying new products, then it is a short term concern.
Will something work out, where they allow a third party to sell/rebuild/make replacement boards? I don't know (prob sell more likely than license to build), we can hope.
In the meantime, it is up to the person and their willingness to take on risk they will end up with a paperweight, but again given all the complaints about poor quality, poor service, that have been pretty common on here, doesn't sound like a new issue.