Active 30% bonus when transferring AMEX MR to Marriott Bonvoy

This came up in another thread, but I wanted to bring attention to it. I haven't seen any promotion announced for this yet, but I confirmed it is working with two separate transfers.

In both cases, I tested transferring 1000 AMEX MR Points to Marriott Bonvoy. I got the standard described 5:6 ratio of AMEX MR to Marriott Bonvoy points(effectively 1.2 Marriott Bonvoy points per AMEX MR point), but I also got additional bonus Marriott Bonvoy points at about 30%. This bonus only show up once the points successfully transfer, and only on the Marriott Bonvoy site.

I did two 1000 MR point tests and they both added the bonus Marriott Bonvoy points, so I've gont ahead and done a larger transfer and I'm waiting for it to complete. Will post back once it's complete as well.