"June 18, 2015 – February 2016. Marriott Rewards will complete necessary system upgrades with Delta Hotels and Resorts.

Throughout this period, members of Marriott Rewards and The Ritz-Carlton Rewards® will receive recognition benefits during their stays. Members will not earn points, miles or Elite night credits for stays. Members will not be able to redeem points toward free stays at Delta Hotels and Resorts.

Members of Aeroplan® will receive 500 miles for qualifying stays at participating Delta Hotels and Resorts until February 2016. Existing Delta Privilege members with earned hotel credit and upgrades have until Feb. 29, 2016 to use them.

February 2016. Delta Hotels and Resorts will fully participate in Marriott Rewards. Members of Marriott Rewards and The Ritz-Carlton Rewards will receive Elite benefits and earn points or miles and Elite night credits. Members will also be able to redeem points for free night stays."

So you will receive elite recognition (upgrade, free wifi, access to exec lounge if there is one, free brekkie) for the stay in late Jan, just not points or night credit.

Cheers.