For a business, it only begins to make sense to make charitable donations when the business starts to make more money than it needs to stay in business. To donate before that point would be to judge that the business is a less valuable use of its resources than donating them to charity; but the owners, being in that business, have already decided otherwise.

I doubt if any cryonics organisation has reached that point. There is no mass market for cryonics yet, but there is competition, so the organisations aren't in a position to charge any more than it takes to cover their costs.