What Raptor Said.
Let's see, your trip sounds like a One Day MEM-ABC-DH MEM.
And now sounds like MEM-ABC-MEM (10 hour trip extension)
There's NOT an Extra Duty Period if reality matches what I think happened.
You Would get the backend DH disruption. Overage of 10 hours equates to 4CHs of pay.
Less $$, but now you have an option as to what you actually do. Which, IMO, is better than FedEx waiting until after your show to decide to Revise your trip as they've intended for the week.
Here's a trip that Doesn't trigger SUB. Saturday AM launch to a short layover with a backend DH. Revised to operate back Saturday night. (MEM-LAX-DH MEM, R1 MEM-LAX-SNA-MEM) Yay, I get an extra...damn it, 2 legs = 1 DH.
Nothing better than landing at Memphis at 10:30 on a Saturday night. Direct to the airport and what runway would you like