If I read the vibes correctly, the whole permaban-reversal thing is due in large part to the fact that the criteria changed a little while back and more granular punishments became a thing, no? That the next step from 'infraction' is no longer 'permaban'? (I love exaggerations.) That's a reasonable reason to let people back in.
But if the reason for a reversal that the member has changed.. well, isn't the reason for a permaban typically that madmins feel like the member will never redeem himself; and that long bans serve as a long time-out during which the member can change? That, of course, should still be the criteria for a permanent boot out the door. (I'm not saying that this has necessarily ever been the reason for a reversal, merely that it probably shouldn't be.)
That said, I think it's a non-issue. Nearly just semantics.
The difference between "two-year ban" and "permaban" isn't a huge one, really, in terms of the outcome. In my mind at least, years-long bans may as well be considered nearly forever bans. 2+ years is a pretty long time. Others may disagree with me; they might have more time-patience than I do.
No, the primary difference between a loooong ban and a permaban is really their connotation, what they symbolize. Long ban? Yeah, you probably got in trouble yet again for the same shit over and over and over again. Got permabanned? Yeah, you probably threatened physical harm to members or stalked them or some such a thing. Go straight to jail; do not pass Go.
Because long bans and permabans are different mostly in what they connote, I imagine that there would be much more member pushback against a permaban reversal than a 'sentence-shortening.' Is worrying about pushback important? Beats me. Probably not, but that's not for me to judge. While a 400-page thread rabbling on about a permaban reversal is alway an eyesore (but also entertaining reading), it does tend to be forgotten at some point.
Banned and Damned should include the unpermabanned and other decision reversals, sure, just so the membership knows what's up.