Every year Microsoft MVPs get reevaluated and some of them are not renewed. Here are some of the reasons why an MVP might lose out. Most of these I have not heard of any Microsoft MVP doing, except as noted.
Violate the Non-disclosure agreement
MVPs agree to non-disclosure terms so that they can be privy to certain news from Microsoft before it happens. This allows us to give product feedback or get ready to help spread the word
From time to time someone attending the annual MVP summit forgets about this and posts something really exciting, and sadly lose their status.
Rest on your laurels
If you start thinking “Hey, I am an MVP, no need to make any further contributions to the community.” you probably won’t be renewed in a year
This is probably the most frequent reason
Misuse the MVP logo
Don’t stalk people, make threats or harass them
One MVP took one of my earlier technical books, reworded and posted it to his site as blog posts. The evidence was clear cut and once it was discovered he was not renewed.
Like viruses or hacking someone else computer