And does the bankruptcy even matter, legally? The company had a business/contractual relationship with its customers. Selling that contract/relationship to someone else, even through bankruptcy, does not let them unilaterally alter it. E.g. if they had made promises, contractual or even just in marketing, a change of owner is immaterial to the other side of that contract/promise.
[1] This is not hyperbole, but an accurate description of destroying functionality that did not require company servers.
[2] False advertising is a crime, after all.