The 36mm DD is unlikely to be discontinued in my opinion, he's saying that to make you buy.
Frankly, the only advantage that an owner will perceive with the new movement is the power reserve; the accuracy depends how ell it's regulated. I`ve said this many times and I think folks still prefer to be impressed by Rolex's claims for their new movement. There;s no reason why their 'old' movement (or an ETA 2892 in decent condition) can`t be adjusted to give this performance. I`ve done it myself several times, I don`t make this stuff up.
I think here's a danger of falling into the 'updrages' trap here. Phones, TVs, computers, cars etc are developing and it makes sense to wait for the next version...........this logic does not apply to watches in my view. If tangible performance was the criteria for choosing we'd all be wearing quartz.
My strong advice is to not be swayed by the new movement factor unless the 70hr power reserve is a real advantage to you.
Paul