What I meant was explained in the part of the post you snipped.
Because we assume stuff and interactions are happening between "camera close-ups" (your actions on your turn) we have zero problem with intentionally non-deceptive spells revealing their nature to creatures during that off-camera scuffle. So, we dont have to push the "confused creature attacks spiritual weapon" into the creature's "on-camera" turn costing it actions.
It's the spells where deception is intended by the spell, where they definexways to defeat it as part of the on-camera close-up "action economy" where we go with "its deceptive until you take actions or do whatever."
Holding the creature-s ability to suss out that this effect is or isnt whatever until their turn, until their action etc and then using that to justify hitting its actions, seeing that as a problem, needing a special exception for only one of the vast number of effects that fo similar things... all seems to not be a problem for us because of that whole model of "stuff is happening off turn too."
Hope that clears it up.
