I have an Amex Plat. When I have booked DL tickets using MR, the transaction showed up as DELTA AIR LINES in the amount of the fare, then there is credit listed for the same amount, showing up as NEW MERCHANT, and the MR are deducted from my MR balance. Later, I get back 35% of those MR since my preferred airline is DL.

This all leads me to believe that the AO on my Amex Plat "spend $375 DL get $100 back" will trigger if I purchase a DL ticket using entirely MR, PLUS I will get back that 35% in MR. Is this correct?