I mentioned to my wife about a month or 2 ago, that Ukraine should totally do something like this.
Russia possibly out of arrogance, seemed to believe that Ukraine would not attack them across the border. So their border defenses seemed pretty thin from what I heard.
We also saw with the Russian resistance cross border action earlier, that they achieved a lot with almost nothing, so an actual military attack would have a very high chance of success.
This is a very good move strategically by Zelenskyj and the Ukrainian generals IMO. It finally puts an end to much of the Russian retorik, and it forces Russia to divert resources on the Russian border, to uncontested areas. And it gives Ukraine something to negotiate with.
If the stories are true, that much of Russian gas exports to Europe are controlled from there, that’s a huge reason to hit Russia there too.
Finally it brings the Ukraine front a little bit closer to Moscow.
EDIT:
It seems to be confirmed that Ukraine now have control of the meter station for gas exports to EU. Allegedly controlling the last remaining pipeline with export to EU.