Some may say Yes, others may say No.

Prior to being a SE, I was on an international long-haul J ticket ex-YYZ.

We were all boarded. And halfway through, we were all un-boarded. For the next 9 hours, I received e-mail notifications of endless delays from AC as well as updates from the concierges in the lounge.
(I am quite sure by that point, the original crew timed out.)

No matter, at close to the 10 hour mark, I'd had enough and asked the concierge to refund my ticket. It took a while to retrieve my bags as they were being kept on the aircraft. Concierge offered to have them sent by courier. I declined and said since I was already there I'd wait. At 1:00am, the concierge walked me to the other side of YYZ and got the bags. I saved AC some dinero for shipping, and we didn't have to stay home waiting for delivery.

While all of this concierge service was done while I was at the airport, it was absolutely the best thing that came with my international J ticket.

I suppose it all depends on one's experience. Perhaps some of the other services a SE receives may or may not be available to all J ticket-holders for all travel.

It would be interesting to hear the experience of others.