I contacted the Marriott Bonvoy Rewards Team. I explained that I have many high level/tier statuses with many different travel, hotel and airline brands. I already have Marriott Bonvoy Gold Elite Status. I provided all of my competitor loyalty programme membership cards, including my IHG Rewards Club Membership materials.
They declined to status match, as is it not with Marriott's policies to do so. However, they did offer me a status challenge. Where I would need to contact the Marriott Bonvoy Rewards Team again, and they would enrol me, in a promotion, where I would have to complete 16 paid nights (not reward nights, or free stays) at any Marriott hotel.
If I complete all of the challenge's requirements, they would then upgrade my Marriott Bonvoy account to Platinum Elite Status, which would last for 1 whole calendar year. I said I would think about it and get back to them, as I am unsure if I could complete the status challenge requirements.
on June 22, 2020