This is not correct.
As I said the affix is mostly fine. 99% of the time it’ll do nothing. the other 1% of the time it’ll completely mess you up and likely wipe you in higher level (20+) keys.
It’s trivial to CC in most situations until you hit a tyrannical boss where mechanics overlap and are already causing a problem; while these are the minority it’s frustrating to have an otherwise smooth run get ruined through “bad luck” (overlapping abilities + timer happens to spawn these Incorporeal + spawn a number that can’t be sufficiently answered).
A similar frustrating situation is the old engineering battle rez which would work most of the time but the small % of time it doesn’t work can really mess you up. It’s a “mechanic” that adds limited depth to the game.
If I were to adjust Incorporeal I would have each cast less impactful (10% loss of dps/hps?) but have each cast a bit shorter cast time.