Nowhere does the linked message say 'for good'. Your heading is misleading in that, and potentially can cause them harm if people think they are closed permanently. It's like all other tourist operations that have large numbers of people concentrated in close quarters (like railroad coaches, cruise ships, hotels, etc), they are taking the responsable approach and closing while this viral thing is prevalent. The alternative is the government/health authorities forcibly close them down.
While the infrastructure is there, remaining intact, it's quite likely they'll reopen.