New Baggage Policy

With Air Canada’s new baggage policy, if I book a standard/basic economy ticket for a domestic flight, will they be able to tell that my fare does not include a free carry-on if I go directly from security to the boarding gate? Would they charge me at the gate if they identify that my ticket is the lowest fare without a carry-on allowance? Does anyone know have they been actively checking tickets to verify whether carry-on is included recently?

Thanks!