Yeah, oceanic flights largely use satellite-based CPDLC today, or HF voice as a fallback, but not VHF in any case (which I suspect is the implicated system here).

VHF Omnirange (VOR)[1] is unlikely to be involved. VOR stations are not dependent on a network. All they need is power. It's 1950s technology. The big ring of antennas next to US 101 just north of SJC is a VOR.

[1] https://en.wikipedia.org/wiki/VHF_omnidirectional_range