I dont know why they would ask for passport copy when they can and going to order entry exit records from cbsa. Instead of ordering by default to cbsa and now they are just delaying it just for cbsa instead of doing it on day 1.
I dont why they ask for passport copy just for few people, at least they should have asked/verified at the interview. Passport will not show any nonstamped entries anyway. All these things are waste of time as per me because they just simply order entry exit or days resided from cbsa directly for all candidates irrelevant of verifying the passports.