That assumes they would run the business as is, indefinitely.
If they sell some parts, fire 75% of who is left, and squeeze the hell out of numerous large corporations who literally have no choice but to pay up... I think they will be fine. Leaving behind a scorched earth, and many lessons learned.
Many large operations simply can not move away from their current stack in less than three years. But they will need support and licenses if only due to regulations. It will be mad, there will be a lot of screaming, and ultimately we will just move on, to newer and better stacks.