“Successor liability”, is it a theory or distinct claim or cause of action?

In a recent decision, Justice Sherwood analyzed the applicability of successor liability as a distinct cause of action, rather than merely a theory of liability in New York.  In Meyer v Blue Sky Alternative Investments LLC, plaintiff Meyer moved to amend

When buying a business, purchasers must take into consideration the possibility of “successor liability” – that is, the buyer’s assumption of the seller’s liabilities and prior conduct upon purchasing a corporation.

In New York, the general rule is that a purchaser of the assets of another corporation is not liable for the seller’s liabilities (