Nah, that's still a bunch of bull, they designed it and have all the documentation. They know all of its functionality, hidden or otherwise, it's "undocumented" functions, it's quirk's, the very ins and outs of it. They probably still have original designers on staff. They have far more knowledge and experience of their own design than any game developers.

And yet RPCS3, an open source PS3 emulator based on reverse engineered research is able to achieve decent playability on most games.

Not to mention, they're a multi-billion dollar company, don't make excuses for them.