In recent times, Kayak has been shifting to push customers directly to airlines and hotels, instead of pushing them through online travel agencies like Priceline.

I suspect this is Priceline admitting that it (and other OTAs) are losing relevance in preference for the meta-search model.

Smart move, and I don't think they're dumb enough to ruin it. Read up on how successful Priceline was with their Booking.com acquisition.