The BTR guys did the 650b Pinner because people pretty much demanded it, not because they necessarily thought it was better, the Pinner was originally 26in only, but so many people made noises about being more interested if it was 650b that they sorted a 650b version as well*.
Whether or not it is better, is not the issue, it was originally a 26er and it very much looks like the punters steered them towards offering 650b, whether that’s due to said punters genuinely believing in 650b, or being hooked by the BS and now too scared to buy a 26 is another matter!
*something the bigger manufacturers are not doing, and the source of most of the grumbles, it’s not that people don’t like 650b, it’s that they are grumpy the option of 26 is being removed so quickly and with questionable reasoning behind it.
At the end of the day parts for your 26er will be available, probably for as long as your frame will last anyway, so it’s no biggie.
It’s only the serial upgraders and meddlers that are going to be affected really, and bikes are a bizarre anomaly really, a sport where for the most part, different parts from different manufactures are freely interchangeable. There’s always been the odd company trying to be more integrated (Cannondale, Klein etc.) and you see it happening more and more now shocks and parts become tuned to the specific bike, and some parts integral and proprietary, I think this is where we are headed in the long run, more integration, more proprietary formats, especially at the top end and at some point your wheels might be the only things you can swap between bikes! Axle standards and widths permitting of course 😉