Flying IST - YUL - LGA

Booked through UA, and connection time in YUL was reduced from 2 hr to 90 minutes due to a flight change. UA said 90 minutes is below their minimum connection time of two hours in YUL.

UA said I can keep the flight "at my own risk" of missing my onward flight due to the short connection time. I have no checked baggage, if that matters.

Is a 90 minute connection doable in YUL? Inbound flight is TK, outbound is AC Express.

Thanks!