He's also down on P-8A (relative to the USN which sees it as the mainstay of ASW) because it can't operate in contested airspace. (By the way, others take the view that the entire purpose of the Chengdu J-20 is to expand said contested airspace and take out HVAAs and tankers.)
This argument is a red herring. Doing ASW in "contested airspace" has ALWAYS been stupid. ASW is a defensive measure. In a war, you search for subs in places where you have important assets you don't want attacked by a submarine. And ever since 1941 when the Prince of Wales and Repulse were sunk by Japanese aircraft, you don't send important assets where you don't already have air supremacy. And absent a hot war, you can do ASW in your own territorial waters and in
all international waters.