Mostly baloney imo. The headline leads one to think there are USAF jets in Taiwan- not the case. The author fails to mention that the F-teens coming out of Kadena are replaced with F-35's and F-22's on 6-month rotations.
The Rand "study" is like all Rand studies- the situation is horrible and we need to spend way more $$$ on the military. It assumes all the fighter jets at Kadena and Guam would be destroyed in a first strike by Chinese missiles and wouldn't be available to help Taiwan, it ignores USAF force multipliers like in-flight refueling or ECM/EW, and it assumes all the Chinese stuff works as advertised.
These are the same guys that gave NATO 7 days if Russia started a ground war in Eastern Europe. I can't think of a single Rand study ever, that concluded "We're in great shape, Russia or China or Iran wouldn't dare to attack US forces or our allies".
Rand's bread and butter is doom and gloom...