Lemme repeeat myself clearly. They were ready to release the PC version at the same time. That's it. And yes, what you say is correct, but they were pretty much done, and already had a stable version, that should work properly.
And remember, they might be a lot of smaller than Bioware, but they didn't have to make the engine this time around, because they are using the same engine as KOTOR2, with not that many changes; so they actually had the time to do more QA. And that means they wouldn't have do as many patches. Beccause Bioware should have found any issues with the engine, during their own QA with the Original KOTOR, and when they released the PC version. Because it uses the same engine, I'm sure that Bioware would have relayed some info on what the issues were to Obsidian.