It looks like Telus had it right! Google announced during the event today that Marshmallow would begin hitting current generation Nexus devices some time next week which lines up with Telus’ October 5 date for the Nexus 5 and 6.
Other devices that should begin seeing Marshmallow next week include the Nexus 7 (2013) and Nexus 9. A recent report claimed that older devices like the Nexus 4, Nexus 7 (2012) and Nexus 10 would be left on Lollipop and given their absence from the list during the event, it seems that this is the case.
As with all major roll outs, things may take a little bit of time so if you don’t receive the update right on the 5th, don’t fret! I’m sure it’ll hit your phone sooner rather than later.