Caesars tier credits earning period is Jan 1 - Dec 31
Caesars status benefit period is Feb 1 - Jan 31
If you earned Wyndham Diamond from stays, you can rematch to Caesars Diamond at end of January
If you earned Wyndham Diamond from Business credit card, your Caesars Diamond will end January 31 unless you renew it (by gambling) this year or next year
If you have MGM Gold you can just park at MGM properties and stay there without resort fee. If you lose MGM Gold, you can get the MGM credit card for free parking, but still pay resort fees.