Adding another DP here.
Amex Personal Plat cardholder for 3 years.
2019 (after first year) - AF waive or points - can't remember exactly
2020 - Denied retention offer due to prior year retention offer
2021 (this year) - 50K MR points, accepted
Process was pretty easy as always. Call number and tell them you are thinking about canceling because of high annual fee. They will transfer you to an account specialist and you can repeat ask and ask if there are any retention offers on your account. Good luck all!