Says who? It can't hurt to politely ask NOW. In person is better. In any case, they should be able to give it to you once the case goes on "trial" on the 9th, assuming they have a copy since the original will have gone to the judge.
Well, Benhoor is relevant, but even more so is People v. Kennedy (2008), where the issue was whether you can directly appeal a TBD without going to TDN. It explicitly compares the TBD procedure to a procedure for administrative violations (e.g. of municipal ordinances) -- the latter can be contested via writ.
In any case, any act by a court in excess of jurisdiction (i.e., what it is allowed to do or not do by law) can be challenged by seeking a writ of mandate/prohibition -- all the way up to THE Supreme Court (of the US) if necessary. This will be the basis for your petition --- you're not seeking a review on the merits (i.e., whether there was sufficient evidence to find you guilty), which Kennedy (sort of) prohibits.
Your "gut" argument is right, but just court rules won't be enough because of the way 4.210 is written, and the Behnoor precedent. You will need to throw in some due process and a good bit of case law -- hopefully, some analogous to your situation. See this example (related to my ongoing appeal) for how complicated it can sometimes get. Post back when you get the copy of the declaration, and the verdict.
Edit: I had a similar situation recently, where the TBD deadline was set 10 days from arraignment, but "trial" set 25 days after. I probably got lucky (still waiting for decision), since the officer was on vacation until well after the date of the trial.

