Definitely a good option, especially with how well instant upair sets up strings. The only thing that truely beats shine>nair is up-bcancel. From shield Up-bCancel is frame 4, grab is frame 7, nair is frame 7, upair is frame 8, bair is frame 10, upsmash is frame 10. Fox's aren't normally that fast though, so that shouldn't matter too much, plus foxs love to shine so it's likely going to be staled.
Fresh shine does 4 frames of shieldstun, and 4 frames of hitlag.
Imagine these are the nine staling slots
.09 .08 .07 .06 .05 .04 .03 .02 .01
If shine is in the queue multiple times you add each value to find the total staling, When the total is .11 or more then shine only does 3 frames of shieldstun, and up-bcancel can even beat multishining. When the total is .41 or more (kinda unlikely), then it does 1 frame less hitlag.
Another thing about upair is it's range. OoS options range go like this:
Shortest first:
Nair - frame 7
Backwards Upsmash - frame 10
Grab - frame 7
Up-bCancel - frame 4
=Upair - frame 8
=Bair - frame 10
Forwards Upsmash - frame 12
Bair - frame 11
Upair will outrange shine, nair, dair, and is about even with a bair.
Made another comparison image
Does not take into account forwards/backwards jumps or drift, so if you were to do that with the aerials they will reach even further.