I just tried it and got shut down.To call the IRCC Call Centre from the USA, dial 613-944-4000. The recording answers as "Welcome to Global Affairs Canada." Answer the automated questions as follows: 1 (for English), 1 (for Citizenship & Immigration), and then 1 again.
After I pressed the final "1" I got a recording: "We're sorry, the toll free number you have dialed is not available in your area. SCT 11." That message repeated twice and then cut off.
Either they've closed an exploitable error or our phone gives away too much information.
Then I tried putting *67 in front of the number: *671-613-944-4000 and got "your number has not been recognized. So I tried again leaving out the 1:
*67-613-944-4000. Same response.
Sigh. Either I'm really bad at this or they've closed an exploit. Our landline is AT&T. I suppose that might have something to do with it.
In any event, nothing has changed since September 7 when they sent notice that it was in process. It's still in process as of November 9.