It's also possible one of the founders just spun up the new service themselves and copied over all of the customer records. If so, they may want to prepare to be sued by their previous investors.
It's one thing to fail after giving it the good ol' college try, but it's another entirely to strip the copper out of the walls on your way out.
Speculation aside, they should put out a statement to clarify the relationship between the companies and what's going on with their customers' data.