Honestly, it sounds like a bad proposition overall. What is Windows Phone lacking? Apps. What will the Nokia Android phone lack? The Google Play store. Hmm.
Other Android based phone are being sold without the Google Play Store, and still sell very well. Disclaimer: those are mostly phone developed for the Chinese market where the Google Play Store is not allowed to be bundle with the phone. See Xiaomi for an example.
Amazon is doing quite well, and making some very sweet hardware running an Android-based OS. I think that with Nokia's ecosystem elements plus a selection of the dozens of Android apps Microsoft makes, plus some China-specific apps, you could have a workable front end to your own ecosystem.
When I tried one (and admittedly, this was the WP7 era) the biggest problem wasn't missing brands, it was awful experiences. Spotify were on there - the app didn't play music 50% of the time. Foursquare was on there, but it barely worked. And so on.
I haven't checked back since because, well, why would I?
Because things have improved? I own a Nokia Lumia 925 and have barely anything to complain about. The thing is I've never been crazy for searching through a ton of crap apps every day like some of my friends. WP8 delivers what I need in a consistent way. I'm glad I moved away from the Android phones I owned in the past 2-3 years.
Well I guess my point was that I have no reason to move away from Android now. A few years ago the experience was terrible and I saw WP as a clean escape from that. Since then Android has come along leaps and bounds.