While the company hasn't given a release date other than “this fall”, new FCC filings for the computer have appeared online, indicating an imminent launch. The filings also show that some Mac Pros will be "Assembled in China", which is odd, considering Apple announced in September that the computer would be manufactured in Austin, Texas.
We're assuming, then, that the Mac Pro's components will be made in the US, and that the computer will be put together in China? Previously, Mac Pros were put together in Austin. They had “Assembled in the USA” printed on them, and they included foreign-made components.
All that said, Apple CEO Tim Cook did emphasised during Apple’s Q4 earnings call today that the new Mac Pro will be produced in Austin.
So, anyway, FTC filings such as these often pre-date official product launches by as much as a few months - for most companies. Apple's products, on the other hand, usually don't appear in the FCC database until right before they're announced or made available to buy.
A great example of this includes the AirPods Pro, which popped up in FCC filings on the same day they debuted.