I now see what you (and Nicolas also perhaps) meant! Note that “reverse the trait for affine operations” really didn’t convey the same to me because there is no trait currently attached to affine operations to reverse! Instead, what you meant was to use the reverse of the AffineScope trait (perhaps call it “ExtendsAffineScope” for expanding or extending an existing affine scope) for affine operations and so the remaining region-holding operations would by default have the AffineScope trait. This definitely makes sense to me.
The original thinking was that we would just go ahead and add the AffineScope trait to the few region holding operations where it makes to hold affine dialect operations (sort of as needed). Because if something isn’t depending on the affine dialect (say the TF or HLO region holding ops) having that property is good as a dead trait. But we can negate this trait for sure - the names I can think of are “ExtendsAffineScope” or “ExpandsAffineScope”, i.e., extending/continuing an existing affine scope that started “above” (in one of the parents) and continued up until.