However, the reg doesn't say "upgrade"....
If, as the Training Dept has said, the only thing restricting an ATP'd/Type'd F/O from exercising PIC privileges on the Dash is a limitation on the license requiring the completion of SOE, how is that not a "Pilot in command aircraft qualification"? A type rating is an aircraft specific qualification!

I can see what you're saying, but my point is that both the letter and spirit of the rule are not nearly so clear as you seem to think.

BTW, if the reg hasn't changed in a decade and this was the interpretation all along, why wasn't this posted along with the 250 PIC debacle or any of the other ATP postings? No, it seems clear that the company understood the provision the same as the rest of us did and BWI is just dumping this on us at the last minute (just like they re-interpreted the 250 rule, changed their minds (thankfully!), and now have this requirement that we have to go to a FSDO and get our flight times "certified" in advance of going down to CQ).

This has absolutely nothing to do with being annoyed about not having a quick upgrade and everything to do with an ATP program that starts in less than a month with a constantly-changing set of requirements (especially getting slapped with a Written retake on such short notice).