That only works if you have 2 viable DPS soulbinds. Not when 1 of your soulbinds is massively ahead of the other DPS wise and thus you use it to slot your best spec specific potency conduits.
It was changed in the latest build :
https://us.forums.blizzard.com/en/wow/t/shadowlands-conduits-update/596481/123?u=raiimir-stormrage
And can confirm, configuring Nadjia for Unholy, switching to Frost, I’m stuck with the Dark Transformation Conduit slotted and my conduit change on 6 days cooldown.