"thwart efforts by Washington, Tokyo and Manila to introduce a military presence in the area through talks that have drawn strong protests from Beijing" [Washington, Tokyo and Manila]
The explicit naming of the trilateral talks as the target of the survey operation directly supports the claim that allied coordination is triggering preemptive counter-access moves by Beijing.
Reasoning from this article
The article frames Beijing's survey not as routine maritime administration but as a direct response to an emerging US-Japan-Philippines security architecture. This reveals a structural dynamic: as US-aligned states deepen trilateral or multilateral access arrangements, rival powers accelerate efforts to establish administrative and physical presence in the contested zones those arrangements target. The mechanism generalizes beyond Taiwan to any theater where allied basing or access talks are underway.