That doesn't seem logical at all. If it comes to an unconventional drone war, SK is the one country that could stand on its own and even obliterate the NK army. The North Koreans are currently getting exterminated as drone fodder in Ukraine, and I doubt there's very little knowledge transfer back home than what South Koreans already know.

I think the deeper reason might have something to do with Chinese designs in North Korea. While China has been reticent to supply Russia, China will see North Korea as a defendant (even if they are the aggressors), and readily supply them with what they need. Ukraine vs Russia is just China vs China at this point.