1.) Minecraft may be be turn into subscription-based game.
The groundwork has been actually going on for a long time since Minecraft Realm was introduced. With recent EULA enforcement, they are successfully destroying a lot of big 3rd party servers. The whole system is ready, and it is just a matter of turning the switch on.
2.) Modding scene will be killed.
I see some of modders are already stopping the work; Microsoft has been very anti-modding from very start, and I fail to see they would change the stance anytime soon. I understand this because of grey legal area on the whole modding scene. Microsoft, as such a big corporation, cannot tolerate legal loophole that may potentially damages its products.
3.) Decrease of youtube personalities and Minecraft
Another grey legal area, and unlike Mojang's stance, the Microsoft's point is... well.. strict. I don't believe many youtube channels will survive longer.
The last two points will slowly kill Minecraft in long run (well, the game itself has been already peaked tho). And I guess.. it's fine. Minecraft has been a huge vacuum cleaner that had sucked out a lot of good amount of indie gaming portion. It's time for more diversity and more options overall.
Minecraft, as a cultural affection, however, is completely different story.