Yes it will work. You're not a lawyer. You didn't know anything about disclosure. Doesn't mean you're not entitled to it.
The crown knows about disclosure. The crown sent you a notice of motion weeks ago. The crown knows it has in its custody an affidavit it is relying on. The crown was required to give you a copy of it. You're only going to get to see it once you are before the court. How can you defend yourself against it without time to prepare a defence?
Do not agree to a new date under any condition. The judge might order one even if you opose it.
On what date were you charged?
On what date in January is the trial?
You have to have a trial within 8 to 10 months. If you agree to a new date the delay byond 8 to 10 months doesn't count because you agreed to it.
Do not agree to it.
If the judge sets the new trial day beyond the 10 month period, even if you oppose the new date, it means you can move for a stay of the charge due to delay.
However, We don't know for a fact that this is what the crown will be requesting. We're only guessing at this point.
Request an adjounment of this motion once the crown produces the Affidavit. You need time to seek counsel. This delay doesn't affect your trial date in January since that trial date is already set.
The crown is trying to convict you. Don't do them any favours.