"All the common shafts" is still a lot of shafts. Hundreds, if not thousands of options out there.

The shaft is the most important part of a club fitting. If you go into it with the decision already made on what shaft you want, find a good club fitter/builder and work with them.

Curious what the common shaft was. If one goes to the catalog there are stock options, some with an upcharge. Then there are exotic shafts. The latter are never available in the standard matrix, and, yes, you can request that in advance when it is in the catalog.
Other shafts may have failed testing for quality or haven’t yet been tested. It is possible that a shaft available from TM didn’t pass Titleist testing.