That's not correct. Concur is an online booking tool that pulls inventory from the GDS. It can also be configured (as of recently) to pull non-GDS content from sources like booking.com, HRS, etc. Marriott cannot currently offer content directly to Concur (nor does Hilton, etc).
Any my point was: Hotels will always want to influence travelers. If a large number of corporate bookings come via booking.com, then the hotels will need to adjust their tactics to continue influencing travelers.
Like I said, its a portal, not an OTA.
But, I'll accept its booking through the GDS rather than from Marriott.com but that some companies are having it configured to pull through other sources. Of course, Marriott promotes that it is always lower than those other sources .....