Just thought I'd relate something that happened to a couchsurfer staying with us. She's from France and is flying home next week. She mentioned that she had booked a direct flight from Halifax to Paris. I knew that WestJet was the airline that offered direct flights, but had heard months ago that because of the Max 8 grounding, they were rerouting people via Calgary, Montreal or via other cities with other airlines. So when I asked our surfer, she confirmed it was via WJ. I did some sleuthing including trying to book flights via Halifax direct and was getting nothing (or seeing flights via other cities).
She received NO emails or updates from either WJ or the 3rd party website she used (it was a company in Spain). As far as I can tell, nothing even showed up in her spam folder. When she put her confirmation code into WJ it told her because she booked thru a 3rd party she had to go thru them. She was able to find a phone number for them and called to find out that indeed her flight had been cancelled. (This is how she relayed it to me). She was able to rebook via Montreal, and it works out OK for her because she arrives 2 hours earlier, so won't lose the train tickets she prepaid for to get from Paris to her city. But if I hadn't know about the grounding, most likely she would have showed up at the airport next week and been out of luck, or in a pickle, at least.
She's been travelling for 10 mos now and got the tickets back in March, before the plane groundings. Maybe somewhere along the way she was notified and missed it. She said she wouldn't deal with 3rd parties anymore.
So just a reminder of what a pain in the arse it can be booking via 3rd party, and a reminder to check your flights. (I will say, Air Canada was very good about sending me itinerary changes for our upcoming trip).