Consoles tend to sell out of early shipments at launch, but only in the primary regions and only because those console makers have to make choices about where they can allocate their shipments between regions, as pre-launch inventory stockpiles don't often exceed more than 3m units or so.
If MS thinks they are going to be more successful this time in regions like Europe and thus increase their stock allocations there, then it's very likely they won't sell out of units at launch. The X1 didn't pretty much everywhere but the UK.
I doubt MS would do this though. I think they will want to try and take the US market from Sony and will focus most of their efforts there. Hence, I would not be surprised to see the same tiered regional launches they did for XB1.
Despite the criticism it won them, don't think they have a choice. If they run out of stock too early in the US over the first holiday, they will risk giving Sony too much leeway. They'll want to be on Sony's neck in terms of hardware sales in the US, for sure, if not ahead. It's their most important market.