Every second this big studio is unused, it's losing money. Even if they own the property (i don't remember, did they ever said they bought it?) And Holo productions are maybe 10% of studio capacity in not less.
There's at least a dozen full time salaries to pay in the studio. They can coast a year or two more, but then investors gonna start asking questions, especially if concert/event revenue won't grow a lot. Doubly so with Anykuro doing their own studio to supposedly ramp up concerts, and who knows what Brave gonna do, they have means for big production (likely stagnate and ditch all vtubers in the end but who knows)