I would say yes it’s a good indicator. With Star Wars opening in the Fall they wouldn’t run many deals during that time. They have soft bookings pre-fall so they want to fill the rooms before Star Wars.
It also means that WDW is expecting very low crowds for the summer. It makes me wish we could move our October trip to the summer, despite the heat. But, given that my nephews go back to school at the beginning of August, it just won’t be possible. Plus, despite the free dining and room discounts, DVC still costs more points during summer vs. fall.
Specifically, this means their resort bookings are down. But, I don't know if we can extrapolate that park attendance will be down, as well. At least to the point that a guest could notice a difference.
I've read numerous times on here that it is offsite visitors that determine park crowds.