If they actually got rid of Bitcoin as payment option, they would at least conveniently make it appear they have actually done so; nothing points at that.
Still active; https://support.microsoft.com/en-us/help/13942/microsoft-account-add-money-with-bitcoin
It would be extremely stupid and nonsensical to get rid of Bitcoin at a time where the fees are peanuts and the volatility has decreased significantly.
If turns out they stopped accepting Bitcoin, which I doubt, it's all political.
The reason for the coins not being credited is likely related to the payment processor and not Microsoft itself.
I would agree with you on the bolded part. Until they come out with a statement or an official of the company was quoted to support such decision from them then its merely speculation. Current happenings and statements made could have been responsible for the conclusion that bitcoin is no longer accepted by the platform which could be a form of technical glitch in that Microsoft as a reputable company would completely stop accepting than to accept and not give users with the required credits. Another way to look at it is that, it might be a form of testing the waters to see the reaction of the people before they decide to pull the plug on the acceptance of that option.
But I don't see this as having any major impact on price as the body language of Microsoft in recent time has been on the opposite that I didn't even know they are still accepting bitcoin and I am sure that a lot of people would have thought that as well and that is why I felt no one is talking about it in the bitcoin discussion section of the forum.