Probably not. You can't really give a monster a "casual" 6th-9th level spell and not give a bit of extra xp for it. Thus traps probably giving xp.
I guess they're "CR appropriate encounters for parties at that level", but a bit less, because they're not actually trying to hit you. Or rather, you can beat the encounter without any ill effects sometimes, which you sometimes can't against monsters (although, sometimes you can because you can see monsters, but not traps. But it's pretty rare that monsters give your whole party a passive perception roll to have an idea that you can auto-mitigate them. Actually, they often do, so yeah. Whatever the DMG says as an encounter appropriate to that "trap level" I guess, but maybe a bit less depending).
Maybe that spell level table is the best guide for some of the CRs in comparison to the DMG's "what does giving spells to creatures add to CR" bit? I'm pretty sure there's one of them somewhere obliquely. Except that does put all traps at like 1-2 CR encounters mostly. I think. That DMG thing might not exist. Or it might assume CR 0 creatures don't often cast lvl9 spells. It might even give an idea of when monsters of a certain CR could cast spells like that. It'd probably be "an appropriate encounter for your party -1 CR + whatever giving something like that equals in spell level +CR". Appropriate encounter CR-1 plus "spell column" in trap UA is easy. First column is zero, next is one, deadly is two. Give or take. Ballpark figure. I'm drinking, and I'm damn well not looking it up or making something proper from this. Add an extra -1CR if they Wis it first
So about -1/0/+1 CR if it's moderate/dangerous/deadly from usually expected CR. Shift it down one or two depending on if it's easy, you're bored, or they kinda noticed it and jacked it up anyway. Maybe always an extra -1 unless they pull something creative, successful or not.
"You are fighting an empty room! But this room is able to cast the vague equivalent of this level of spell at you with a trap (from trap tables)! Thus it's worth this CR to survive/beat/not-get-destroyed-by this trap! Maybe more if brain work was involved! Unless you noticed it first and stuffed up anyway!"