Apples, Oranges, and Bananas are sort of related...
1) I am also not connected to either company (other than as a customer). I am a retired IBM employee. Knowing a bit about IBM, they won't release anything, unless forced to, or, unless their lawyers, voluntarily, and without cost, do all of the legal things, that need to be done, to clear all of the possible concerns about releasing the code. Since it is unlikely that anybody will (could) force them to release the code, and even more unlikely that their lawyers will do anything, at all, without payment, I expect that releasing code is never going to happen. In fact, I wouldn't be too surprised, if the whole thing is erased, when the last contract is finished. IBM has no interest in quality products, they simply want to sell whatever they can, that will make them money. OS/2 is far too reliable to make money at consulting, when they can make big money converting users to Linux, or Windows, and then keep on making money by fixing the problems that arise.
2) Mensys/SSI could do things like that, IF, and only IF, IBM would foot the cost. IBM has basically said, that they won't do anything for eCS, other than what SSI/Mensys can already do, by contract. I suspect that they are totally amazed, that eCS has got as far as it has, and they would prefer to simply forget all about it.
3) As noted, there is no access to source code. All that SSI/Mensys can do, is document a problem, and invoke the service contract, that they hold for the OS/2 product. IF, and only IF, IBM decides that they will fix a problem, they will produce a one time fix (IBM would, probably, charge for the time to decide that they won't fix a problem). IBM would also produce new features, IF, and only IF, the customer (SSI/Mensys), is willing to foot the bill, which would probably be well into the millions of dollars, which would push the cost well over what could be handled by the OS/2 community. It makes more sense to sub contract to another company, but they need to start over, reinventing the wheel, because they really don't have anything to start with, and those who do charge for their services, are working as cheap as they can, simply to make eCS viable, because they believe in the product. Many others do their part, for free, just because they want to help. The bottom line is, that eCS could be developed further, faster, if the price was doubled, but then the market would dry up, and blow away, leaving us with nothing.