Microsoft has accepted Bitcoin as a form of payment for a long time.
Recently the company did a step back and remove the option to pay in Bitcoin.
The reasons specified :
1. High fee on transactions
2. Long delay to get confirmation of the transactions.
3. Extreme volatility
Based from the information you have provided. The backing of microsoft seems to be valid on a business standpoint and not on a general market as a whole.
At the end of the day they are still a business organization that focuses on profits to keep their business going. Thus, we should be too salty about this move by microsoft.