I was surprised as well. I now remember how I gave this a shot back in March 2024 with low expectations. I figured it was only 1,000 MR points, so no biggie if it didn't work.

AwardWallet doesn't think this works, but it did for me, twice:

Just keep in mind that point transfers do not extend the validity of your flown miles. That means you should only transfer points to top off your account right before redeeming miles for the long list of Flying Blue sweet spots, such as the monthly Flying Blue Promo Rewards.

https://awardwallet.com/airlines/fly...-miles-expire/

Same for One Mile at a Time:

Air France-KLM Flying Blue mileage expiration policy

Air France-KLM Flying Blue miles expire after 24 months of inactivity. Note that only select activity can reset the expiration of your miles, and that includes crediting a flight to the program, or earning miles with a co-branded Air France-KLM credit card. Other points earning activity won’t reset the expiration of your miles. Flying Blue elite members are exempt from having their miles expire, for as long as they maintain their status.

https://onemileatatime.com/guides/ai...iration_policy

As with so many things we see here, there is often a big difference between T&C, rules, etc. vs. what actually happens in practice.