But people will buy an XBox rather than a PS6/7 if they can't play CoD on the latter... It's not like people are already tied into a console 1-2 generations in the future, so this would influence what console people buy next.

With Minecraft most players play on PC and frankly taking it off Mac and Linux would make a lot of business sense for Microsoft, however as it's Java and how easily modifiable and portable Java programs are, they know people would just get it working anyway. The same does not apply for CoD, where nearly everyone plays on console, and a significant part of what console someone buys is what games they can play on it.