I think most of the bikes in last 10 years or so have been pretty good reliability wise, I have clocked 50,000 miles on 3 1X90 adventures, mates 1190 was flogged of at 68k and going strong.
Service items will be around for donkeys years regardless of what happens to KTM, and most manufacturers don't keep spares forever anyway, although its why I dislike TFT screens, keyless ignitions and semi-active suspension as they are most likely to cause you a headache down the line either due to costing more than the bike is worth, or simply no longer available....
...and with all modern bikes you have expensive ECU's motors operating the throttle and all sorts of guff that will prevent them running on forever like a lot of 80s and 90s stuff does.
Id still buy a KTM if the price was right, people happily pay £20k for a GS with warranty, but not £12k for a new KTM with a dubious one right now - but its still under 3-4 year old out of warranty BMW / Ducati price.
Come spring if nobody has bought my 1290 I am going to service it and ride it for another year, then maybe next winter get the suspension serviced / reworked, ECU remapped and just keep riding it until it falls apart, not like the new stuff is much better anyway (goes for BMW / Ducati etc)
With all the dealers stuck with stock (not just KTM) I think if you have cash and fancy a new bike there has never been a better time.