NO, Microsoft should really NOT release an android phone, there are way too many options already on the market, it would just be useless...….
UNLESS - the phone they release is somehow a game changer or totally new form factor.... like the rumored Andromeda device. If andromeda is all that it is hyped up to be, and it runs android meaning it can run any of the billions of android apps, THEN it may actually be worth releasing.
UNFORTUNATELY, if Andromeda was released as a device running Windows Core, and has the ability to make phone calls, no one is going to replace their phone with it, since it won't have access to the billions of android apps. Now, if it is marketed as a Phone Companion, then there are possibilities.
Now if it ran Windows Core, but could ALSO run android apps (like some early builds of Windows 10 Mobile did), that would be TOTALLY AWESOME!