To Hyatt it’s the same thing -

X Rate was offer let’s say in March so you booked under X rate. Since March the rate changed 8 times. The current rate is X + $82.

Shortening a reservation requires rebooking, which means you’d get the current rate which is X + $82 per night.

Neither Hyatt Corporate nor Twitter, nor your Concierge can do what you asked, because it’s not Hyatt’s policy.

In your case the hotel was nice enough to adjust the stay to one less night. My guess is because it was Hyatt Regency La Jolla which is one of the worst San Diego properties, it definitely does not deserve a Category 3 designation. I would much rather stay at the Hyatt House Sorrento Mesa (same category and typically lower cash rates, or The Hyatt Regency Mission Bay which also has similar cash rates and is also a Category 3). We travel to San Diego pretty frequently (we have family in Oceanside but we stay in the Gaslamp when visiting).

Anyways be thankful the hotel went above and beyond. Also, try Bronx Pizza (really close to your hotel it’s the Best is SD) and definitely get Phil’s BBQ both I’d highly give my stamp of approval.