Is there any idea if any of the big companies still supporting win 8.1 apps like WhatsApp will make win 10 apps?
I really think that there's going to be a sit and wait approach by third parties.
I can think of two possibilities, one is that they're sceptical about the income that supporting windows can bring, versus using a browser, two they've got years of data to show how beneficial supporting apps has become for other platforms, so they can weigh up whether adding a third one will make money or just be a drain.
I have a suspicion that there's app burnout in a lot of the industry. It costs money, probably doesn't generate income when compared to the outlay, and as a result, isn't worth it, on top of that, good ideas/features can easily be usurped by apple/google or any other large company.