That's a reasonable concern, but in practice the likelihood of the product being killed by malicious counterinteroperability games by Apple (and the other proprietary backents too) is far higher than the chance you'll be screwed by the manufacturer.

Beeper isn't in a business that's every going to make them significant money. Their core value proposition is, ironically, that reverse engineering iMessage is "just hard enough". If it becomes too hard, they fail.

But if it becomes too easy, they fail too because everyone will launch Apple-compatible chat apps! In fact the worst case is that the protocols end up standardized, in which case they'll have to compete with genuine open source implementations.

Basically, I'm absolutely in their corner in this fight, but I'd never bet on Beeper as a product.