25.H.2.b Trip Rescheduled Outside 4 Hour Window
The trip is rescheduled to begin more than 4 hours prior to its original showtime or to terminate more than 4 hours after its original termination time. Trips in this category must be offered to the pilot as a reassignment trip prior to the pilot being placed in substitution.

25.H.5.a Substitution Trip Assignment
The showtime and scheduled termination of a substitution trip must be within a pilot’s substitution window.

25.H.10.b.ii If a pilot declines a reassignment trip, he shall remain eligible for substitution.

You're in a SUB status due to the first paragraph quoted.
They "must offer" the trip as a RAT.
Your refusal of a RAT trip is not the same as declining a SUB trip. Refusing RAT just puts you back into SUB status for the SUB window. As we all know, long SUB windows for commuters are a pain. If you live in MEM it's still a pain. But you don't go into OTP status until you turn down a SUB trip.

That's how I understand it, anyway.