Again it would work, but technically that would be a violation also, because you are paralleling the "white" neutral wire. That wire is too small to parallel in accordance with the CEC. It is as much work to install the three wire as it is a four wire...
If you used a three wire...
If you separated the neutrals in the light box and put the "feed in", the "feed out" and the "feed" down to the switch as a separate connection, then connect the fan to the neutral from the light switch, technically you would not be paralleling the neutral any longer.
This would be confusing installation for anyone following you in and would not be considered a "standard practice".
Cheers
John