I'll leave you with this. Who made Windows Phone popular? It wasn't MS.
No-one made Windows phones popular, that was the problem, though granted, Nokia worked as hard as they could and did actually get a half decent market share in some countries, but by that point it was too late. Microsoft needed to have their OS ready around 18 months earlier than it was, and then Nokia might have had a better chance of making a go of it, but by not having a decent OS of their own, and then having to wait on Microsoft, it was all too little too late, and the writing was on the wall. Microsoft then decimated what was left of Nokia after purchasing it (can't blame them for this as it was losing a ton of cash still), but this left them with just the last couple of Lumia's and nothing else going forward. At this point, market share began to freefall and has done ever since, one model from Alcatel, another from HP, and possibly a couple of other OEMs is not going to save them now. It's a shame as the interface on Windows phones is way better than IOS and Android imo.
Another reset of the OS from Microsoft will effectively kill their phone OS completely, those that have hung on until now (much like myself) will finally leave, and unless whatever Microsoft come up with next is truly groundbreaking, it's game over for them in mobile. All this talk of running x86 app on Arm devices is all well and good, but average Joe will not see the benefit of this at all, there may be a case for business users, but they'll never have a mass market product with this approach. If they want a mass market product, it's the hardware that will win it for them, much like the Surface range of products, but a Surface phone will need to be something completely fresh, not just another rectangular slab, maybe something with screens both front and rear perhaps, that can then fold out to work as a single larger screen... just an idea, but basically it's got to offer something genuinely useful that hasn't been seen before and can't be copied quickly by others.