The processing time for the Canadian passport might be longer, so I suggest you check with the consulate. This situation appears unusual to me. In my understanding or recommendation, the law implies that once you take the oath of naturalization, it's the same as in the USA. I'm unsure about Canada's specific rules, but when you take the naturalization oath, you typically cease to be a citizen of any country except Canada.
You may need to explore options to expedite your passport application, perhaps by paying emergency fees or any other required charges. I believe you should be able to enter the United States with a Canadian passport and an I-20 without needing a visa. Canadian citizens usually do not require a visa for entry.