First, I don't think it is an issue of getting them back into stock for buyers, it's people buying as many as they can when they hit shelves to try and turn a profit. Jump on Facebook Marketplace, you will see all sorts NIB Switches for sale above retail.
Second, the Switch will mostly likely be to almost 100 million units sold in 5 years (if not over it), so anything less than that is a joke. Add in two or three more solid years of 15+ million units per year and a couple more years of it selling out inventories and there is no reason not to think that this console will not easily be pushing to beat the PS2.
Any fears of it having the Wii drop I think are funny, 4K gaming will not kill the Switch like HD gaming killed the Wii. Add in the huge handheld market as well that is still migrating to the Switch.
Nintendo with the Switch:
