Is this about bricks and mortar gambling companies? I don't see online casinos going broke, especially if they are from other locations. For them it is just an integration of the Ukrainian language in their web interface. It is not that they run a totally independent and different company in Ukraine.
I wonder anyway how is the Ukraine going to stop online casinos from abroad? There is literally no country in the world that managed to do that because of VPNs.
I also don't know about the statistics of gambling in Ukraine, but the financial damage Covid has caused s probably so substantial that a gambling tax is a drop in the bucket at maximum I would guess.