I honestly thought that FIFA would somehow get this to Morocco just to screw the US. I'm very happy about this!
It probably would've gone to Morocco under the old voting system, but the new one opened up voting after the backlash with the corrupt vote that gave Qatar the 2022 World Cup. The reps for the North American joint bid also did a lot of campaigning on their part to win over votes to their side.
So do the US, Mexico, and Canada all get auto bids?
That’ll be at FIFA’s discretion, because of the situation of there being multiple hosts. I can’t imagine they wouldn’t get them, though.
With the expansion it is a sure thing based on precedent set in 2002, when Japan and South Korea both had auto bids.
Now to speculate what would happen if the expansion didn't go thru? US would have an auto bid since they are hosting the most games, and Mexico and Canada would fight it out in CONCACAF. Whoever is higher would earn a bid. This is a moot point since, if FIFA didn't have the expansion, the WC2026 would have gone elsewhere.