Is MSY the final destination on the original ticket, and is it also the final destination on your replacement ticket?

If so, it is important to know what time you were originally supposed to arrive there, and what time your rebooked ticket gets you there. It is the time of arrival at the final destination that matters.



If, instead, you always were travelling on to MSY separately from this ticket (self-connecting), then it looks like no compensation is due. The KL cancellation on your IAH-bound ticket led voluntarily (albeit for a reason not especially of your choice) to a change to a new ticket to a brand-new destination. New journey with new destination - therefore no question of a delayed arrival, and therefore no compensation for a delayed arrival. You would have had to arrive in IAH (assuming this was the final ticketed destination) as per the original ticket with a sufficient delay in order to become eligible for delay compensation.