Good call on their part.
Anxious to see what this means for Toronto as I'm driving there from Ottawa, just booked my hotel recently AND took my 2 personal days for the year on Monday and Tuesday (I have lots more but the personal days where the only legit ones I could take).

Anyways, for me....

Best case scenario: He's actually fine by Monday, although from what I've read, bronchitis can take 2-3 weeks to fully heal.

2nd best case: postponed to some (any) week end.

bad case: postponed to a weekday. I'm out over 600$ in tickets and hotel.

worst: he tries to sing and scraps his vocal chords even more.