You can bet that countermeasures are already in place or are being developed now. Jamming of commercial drones is doable. However, it is ridiculously hard to jam software controlled radio equipment. Especially military grade hardware. SpaceX demonstrated this recently when they got past Russia's top of the line hardware. The energy requirements balloon to ridiculous levels when you are talking about broad spectrum jammers doing area denial. In addition, such jammers make excellent targets since you know exactly where they are. If drones could be targeted it makes jamming a lot easier, but still difficult.

One thing we can expect is home on signal anti-aircraft batteries and anti-loitering munitions that seek other loitering munitions. I wouldn't be surprised if this is one of the last big wars where such COTS drone tactics are successful.

I’m not sure how effective signal jamming would be against COTS quadcopters. It’s relatively easy to provide on-loss-of-signal instructions to the navigation microcontroller. Perhaps it could be a return to set location command or a home in on signal jammer and explode command.

>or a home in on signal jammer and explode command.

Congratulations, you just invented the anti-radiation missile.

The drone space seems to be speed running decades of SAM and combat aviation tech.

You're saying all we need to defeat these drones is lure them into a jammer and destroy them all at once with conventional air burst munitions? If you want to be fancy use a helicopter to make your air defence solution mobile.

Some kind of middle ground platform with the largest commercial multicopters as a cost effective base but with some jamming resistant communications would be the sweet spot. Perhaps 5kg payload and a few km range and some autonomy such as being given permission to autonomously drop munitions on specific target signatures in specific areas.

If it can be entirely radio silent within the last mile radius (records video for later transmission, finds targets and attacks without intervention) then jamming would be extremely difficult.

>Wouldn't a COTS drone be relatively easy to jam

Have you heared Link 1?