xiaobaitu, pjiang or anyone have experience, please help!

US H1B, Plan to have a short visit to Canada.
when I check the Canadian consulate general website, I found the following statement:

"When applying in person in Detroit:
We attempt to provide same-day service to all temporary resident visa applicants, but we cannot promise that a visa will be issued to you the same day. For Certain counties a waiting period will apply. "

To my surprise, China is among the list of the countries that need a three week waiting period.

Dose it means, if I apply visa in person, I have to wait at least three weeks to get Canada visa?

Is a new policy? Because I heard a lot of people have applied in person and get visa at same day in Canadian consulate.

Please help to clarify this issue, Thank you in advance.