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If you are not officially divorced, then you should mention 'MARRIED' while sending application to IRCC. No exceptions or it will considered misinterpretation.

If you have already sent your application with 'MARRIED' status. You don't need to worry
And yes I have already sent my application with 'Married' status & received AOR last month.
 
You only need to update them when it's official or your case will get really complicated and might confuse the officer.
 
Talked to another Immigration Law firm today & they told me the same thing, I need to let the immigration know about my situation. I could submit an affidavit along with my update to make sure my bases are covered.