I'm told that at least one vendor is going to lose a lot of money when its investors find out about this.

That depends... how about if it were presented as "our new models come with a feature that will dramatically lower support costs"?

I doubt that investors would be savvy enough to care but it would be a stupid move, nonetheless.

Besides, the server is where Linux matters, not consumer hardware.

Investors are savvier than you'd think. Even on a rumor that the vendor is doing an exclusive lock-in with MS, I'm sure you'd see the stock price dip. Investors spend all their time looking at news reports in their target industry, so I'm sure they'll notice something as big as this.

But what product will they be putting the lock-in on? It may not matter, as we've seen with mobile OSes which, from the perspective of the median buyer, are locked in.

mjg59 wrote the original blog post - he might know more than you.