Theory: China is sending a variety of “objects” into US airspace to a) see how quickly they are detected and b) to see how they eventually are destroyed. The US is sending in the F-22 because it has the smallest radar cross section in the arsenal, along with extensive electronic warfare capabilities that would permit it to blind the Chinese device before its destruction, thus limiting Chinese knowledge of the defensive capabilities.
If there is to be a war in the Taiwan Strait, China needs to know which offensive objects it can hurl at Taiwan without detection. And for those objects that will be destroyed, it wants to know the parameters: timing, detection distance, etc. Any war over Taiwan will be conducted with many autonomous flying vehicles of different types.
If you send a bunch of targets and the enemy is vigilant and attempting to mark all of them and destroy them ASAP, you know exactly how good their detection & response systems are, and, crucially, you'll find any blind spots.
If they're ignoring all of them, you learn nothing.
If they're responding unevenly (tackle some fast, ignore others), you get some signal, but a lot of noise.
measurements and statistics intelligence. MASINT. is this for Europe, I could see that, but being the continental United States, there are easier ways they could've ascertain that data.
My cynical take is that these incidents being newsworthy where they previously may not have been just means a new military spending program will soon be announced.
If there is to be a war in the Taiwan Strait, China needs to know which offensive objects it can hurl at Taiwan without detection. And for those objects that will be destroyed, it wants to know the parameters: timing, detection distance, etc. Any war over Taiwan will be conducted with many autonomous flying vehicles of different types.