I would note that while not explicitly clarified, it's likely that corporate TA rates at large companies that force employees to use a corporate travel tool like Concur linked to a corporate TA... will not be impacted by this. If there are any reports to the contrary, it would be of tremendous interest.
Marriott has mentioned that now when they go back to renegotiate margins with 3rd party TAs like Expedia, Travelocity, they intend to negotiate rates with lower margins for the 3TA. This may be part of the game- 3TA's generally excluded, unless maybe they make the deal with Marriott favorable enough to be carved out as an exception as a qualifying rate.
Or just a move to force most bookers to book on Marriott.com exclusively, or get cheaper rates sans elite benefits.
To be abundantly clear
on current terms:
Originally Posted by MR T&C
2.1.e. Qualifying Rates. A “Qualifying Rate” is the rate a Member pays for a Stay in a guest room at a Participating Property which qualifies to earn Points or Miles unless the Member stays under a “Non-Qualifying Rate,” as defined in Section 2.1.f. Unless otherwise specifically stated, Members will receive their membership tier benefits during stays on Qualifying Rates.
2.1.f Non-Qualifying Rates. A “Non-Qualifying Rate” is a rate a Member pays for a Stay in a guest room at a Participating Property which does not qualify to earn Points or Miles. Non-Qualifying Rates are those booked using the following methods:
i. The guest room was booked through a tour operator, online travel channel or other third-party channel including, without limitation, expedia.com, hotwire.com, priceline.com, orbitz.com, booking.com, travelocity.com;