Yes, and then they'll have the cost of rebuilding that entire area. They've totally destroyed much of the existing infrastructure such as the steelworks in Mariupol. They'll need to rebuild houses, industries, roads, bridges...how on earth do they think they'll manage that if they're chained down by sanctions? If they simply "print more money", it'll send inflation skyrocketing.
We've commented before about the poor quality of operational planning by the Russian military. However, there's a bigger problem at play: the total lack of strategy is breathtaking.
Or they simply leave it un-rebuilt like they did much of East Berlin and East Germany until the East and West reunited.