That makes sense for the 8-16 players who reached a QF in the event (or two events) the week before; for all the others, it would be two week without match-play after losing early in an event.
It was never a problem in the past. It's only in the last decade that we start to see a lot of lazy top-20 players (events like Sydney, Eastbourne and New Haven used to have amazing line-ups, and (semi-)finalists often went on to win the slams after that...)
1999 New Haven: Venus won the final vs Davenport, and then got to the US Open SF (lost vs Hingis), but won the doubles
2000 New Haven: Venus won the final vs Seles, and then won the US Open
2001 New Haven: Venus won the final vs Davenport, and then won the US Open
2002 New Haven: Venus won the final vs Davenport, and then got to the US Open F (lost vs Serena)
2003 New Haven: Capriati won the final vs Davenport, and then got to the US Open SF (lost vs Henin in a 3rd set TB)
2005 New Haven: Davenport won the final vs Mauresmo, and then got to the US Open QF (lost vs Dementieva, despite having a MP)2003 2006 New Haven: Henin won the final vs Davenport, and then got to the US Open F (lost vs Meldonium)
later, there was Woz winning New Haven and getting to the US Open final in 2009...
ps: Davenport is the queen of losing New Haven Finals...