As a manager for a Verizon retailer, here's my perspective:
It's VERY likely Verizon won't give two *you-know-whats* about Microsoft. They don't really need Windows Phone to make money. The only reason they would potentially want to get close with Microsoft is if Apple and Samsung flex their muscle too much. Verizon can't bow to Apple and Samsung too much, or else their whole business is controlled by these other companies.
Currently, Apple holds a lot of power over carriers, because they know that without Apple, their business is in trouble. For example, Apple has special rules. The iPhone CANNOT be displayed next to another type of phone. There can be NO color around the display, including Verizon red on the pricing card and other stuff directly next to the phone. Funny enough, the iPhone and iPad cannot also be displayed next to each other. Apple feels the iPad and iPhone sell better when they are not next to each other, but spread out. And Verizon gives in to this. They practically have to.
Thankfully, Samsung doesn't have crazy rules like this, for the most part. But it is scary to Verizon to have to do what these large companies say. By giving power to a 3rd company, Microsoft, it takes the reliance on Apple and Samsung.
However, if Microsoft can't sell phones, it's a waste for Verizon to put any eggs into a basket that won't benefit them. It's just a financial loss, which is the bottom line. Does this make Verizon money? No? Ditch it.
This is the chicken-or-the-egg debate. If Microsoft did a better job with Windows Phone and made it super popular, Verizon would love to support them and sell their phones. But if Verizon doesn't want to put any skin in the game and promote, help sell, display phones, etc., then phones won't sell, either.
With past attempts at supporting Windows Phone going sour, Verizon is probably more likely to give their support to another Android manufacturer like Motorola. The Droid line sells really well. You might not hear about it, but trust me, the Droid Turbo sells like hotcakes (whatever that saying means). It's a fantastic price with comparable specs to the GS6 (maybe not as good of a camera, but definitely better than average Android phones, plus 2-3 days of battery is phenomenal!). Not only is the Droid line getting really good in the past year, it's also exclusive to Verizon. That's a winner. We know how much Verizon loves exclusive stuff. This is a safer bet for them. With the Droid Turbo 2 and Droid Maxx 2 coming later this year, Verizon probably care more about Motorola than Microsoft at the moment.
But I could be 10000% wrong. Just an observation. I started working at Verizon about 1.2 years ago with the hope that I'd open people's minds more to Windows Phone. Not force them away from what they love, but at least get them intrigued and perceiving Windows Phone in a better light and being more open.
I wouldn't say I'm pessimistic now, but it's tough to convince people that are already so invested in iOS or Android. And I can't blame them. It's hard to teach an old dog new tricks. The best thing Microsoft can do to get Verizon reps to sell Windows Phones more, is to get Verizon to beef up commission on their phones. It works.
Apple products pay out the lowest commission (Apple has this thing about the iPhone sells itself, no one needs to talk it up). Android phones have great commission. Windows Phones have similar commission. If there was a monetary incentive to employees, and proper training, not just a stupid Flash video once a year, maybe reps would push it more (if the stores even bother stocking Windows Phones, which many don't anymore).
Sorry for the rambling. Thanks for reading, guys. Just needed to vent a bit.