Look at the thread you're in. The majority here, by a fair margin, said they like this change. What's your basis for declaring this is ill-advised in this instance, given both their polling data and the resulting comments here all seem to indicate the other direction?
Well, there's always the ubiquitous disclaimer that internet comments and online polls don't necessarily mean anything.
That said, I personally think it's ill-advised because - even leaving aside the knee-jerk dismissal of tradition as a legitimate factor - if you follow with the idea that "devils are corrupters, demons are destroyers," then succubi make much better demons than they do devils.
The idea that succubi - or at least, D&D succubi - use sex and temptation to lead mortals down a dark path always struck me as being misguided. Succubi are there to
kill people using sex; that's why they energy drain you with a kiss (or any other carnal act). Most people in the game world are 1st-level, which makes even a single instance of passion with a succubi deadly, and even most heroes won't be able to withstand very much before being reduced to a dead, withered husk.
True, succubi do often use deception to accomplish this, but that's a question of methodology; "destruction" and "corruption" are goals, and are silent as to how those goals are achieved. You can use subterfuge and lies to get into a position to put a knife in someone's back, and they'll be just as dead as if you'd torn their head off; that's the lesson in destruction that succubi showcase.
To me, they've always been quintessential demons; they want you to pucker up and
die.