As one of the magazines pointed out, the USGA has announced significant commitments to both Pinehurst (as a new home) and Bandon -- ie, the east coast and west coast, the pro game and the amateur game.
I imagine that announcing these long-term relationships-commitment also helps the USGA's bottom line, and serves as significant leverage, ie
every *other* course that might want to host a USGA event now knows that they'll have to make a very significant offer or risk the USGA saying 'that's okay -- we'll just go to Bandon/Pinehurst again'.