I think the main thrust of the article is that many systems are vulnerable to control channel interruptions. In those scenarios, a jammer can be far less power

I think the main thrust of the article is that many systems are vulnerable to control channel interruptions. In those scenarios, a jammer can be far less powerful and much harder to detect. In many cases, the underlying encryption system for communications is particularly vulnerable to disruption. In those cases, individual bit flips caused by intelligent jammers can cause the loss of entire frames. BTW, the public safety standard for digital radios (P25) is also vulnerable to this sort of attack. IIRC, jamming the digital system often had the side effect of getting users to switch to less-secure (unencrypted) analog modes that were vulnerable to interception.