If CIC specifically mentioned to provide CBSA Traveler History in request of RQ, they may not do much further until they receive it.
If I were in your shoes, I would write a Cover Letter addressing to CIC stating that I have applied for CBSA Traveler History and would submit one as soon as I receive it. I would attach a copy of letter sent to CBSA. I would also mention how long and what US visa status did I possess in the past with a copy of evidence. I would also add that I haven't been to USA since that last date with evidence if possible. I would attach a copy of paystubs, work experience letters if working, university transcripts if student to provide an evidence that I have a strong permanent connection in Canada. I would also attach a copy of itinerary or boarding passes(if you have saved them) for all the travels outside Canada.
It all depends on your situation and evidences you can furnish. That idea is to provide a CIC officer with as much evidences as possible so that he is convinced that whatever dates you mentioned in residence calculator in citizenship application is correct and you have a strong connection in Canada.
You might have all the exit/entry dates stamped on your passport. But as you are aware, if you travel between USA and Canada, the immigration officials don't always stamp the passport. Not every applicant has been honest in declaring those unstamped information. The CIC officer might just want to verify that with CBSA Traveler Record. You might just be paying the price for the abuse the past applicants have done.