YYZ has been using DM (no F service), GM/J, SM/PEY, and none of the above.
They check your BP and travel document when you are in line and redirect you if you are not in the correct one (knowingly or unknowingly).

There has been trials at YYZ for the general Y line by row number (front Y and rear Y)

Having flown AA with family over Christmas/CNY, I love their different sound for boarding out of sequence.
At CLT there were five who had to do the walk of shame trying to board with groups 1-EXP or 2-OWE

That's not how it should work though, SL & GO should both be entitled to the J queue

Also no point if (like VA IIRC) they make the gate scanner refuse a boarding pass until it's the turn of the group no. printed on the BP (even if a FFP Card is manually shown)

Obviously they're not adding more lines at the gate. This is just about calling passengers up in order, using whatever space is at the gate. It is quite awkward when CX try to force J/PE/Y lanes even when there's no room for it. Plus most other airlines do groups, so people get it (or will familiarize over time)

To self: you're missing the point....

Ahhh, I get it now.

If you're a status or F/J pax, you're probably not going to notice much difference. But for economy with low or no status, it might make a difference if they enforce it.

Follow up question: If status and/or J/F pax arrive at gate late (as I tend to do, at least), will there still be a well-guarded line just for those pax?

One of the things I've long appreciated about CX is how the front of the gate is usually very well maintained for F/J/status pax until the end. So you can show up 20 minutes before and even if there's still a long line for economy, there's no problem boarding. Hopefully this isn't lost with the group boarding change.

Possibly the way the US carriers do- atleast at times - rope off the entrance for the lower numbered groups once those in that queue have boarded, and then manually allow the later arrivals in through that (now roped off) queue.

In December, at SYD someone was looking at row numbers when people joined the Y queue, and directed the front half of Y to a separate holding queue. This was only allowed to board after (most of) the back half of Y had boarded.

To me it did not make much difference to letting statusless Y board in any order.

I am not sure they have the manpower for all this at outstations? One benefit of the crazy long line approach is that they don't need many people.

But it is crazy for Y passengers. If you somehow missed that it's time to line up for a minute you could wind up in a situation where you have to walk for a very long time away from the gate to find the end of the line, and then discover you're one of the last people in the cabin with potential implications for overhead baggage.

YVR has been doing this for quite some time already IIRC (Splitting Economy into 2 queues for front and rear). This was taken from early 2023.
https://cimg2.ibsrv.net/gimg/www.fly...6052d0f152.jpg
RIP - Marco Polo Club Green Member PEY priority boarding

While interesting, I don't believe these are the exact same as what the OP is describing. IME, I got an email in advance similar to the OP, and then the boarding pass actually has a boarding number on it. Mine had a big 1 printed on it, and I saw others with different numbers.

I think what you're describing above is the same as what ultrawin above me is describing at YVR.

What if a DM is travelling with companions who have no status? It used to be the case that companions can go to the F queue together with the DM passenger. With this boarding number in place, does that mean only the DM can board in Group 1, and the non-status passenger/companion will need to board in Groups 4/5?

But if you're at a single jet bridge station, you just get stuck on the bridge with all the Ys. An unpleasant wait on a no air con jet bridge at JFK in the middle of a NY heatwave comes to mind...

Isn't that what they do already? I thought they boarded Y by rows (and have for a while).

If they are trying to board via rows for Y, it is not a trial but another attempt at it. I remember seeing this method at various outports such as KIX and BKK(?). I am pretty sure they tried doing so at HKG, even announcing that they would first board those with priority boarding and then those at the back of the plane.

The success rate varies but I contend that it depends more on the behaviour of passengers. At KIX, I remember the kids could not care less about announcements and would rush to form a line once the boarding announcement was made. It was always a bit chaotic there.