Are you trying to provide theory to say that getting out of that situation with a hurtbox is a better option than getting ouf of that situation without a hurtbox?
When up-air, down-air, neutral-air and the invincibility frame(s) on Shuttle Loop all have shorter start-up time than the Dimensional Cape? Oh, and hurtboxes? When is your opponent caring about hurtboxes when he/she is getting counter-attacked by a character with a sword that has laser-like properties? If your opponent gets hit by one of these counter-attacks, depending on where the opponent is when he/she gets hit, the situation could actually shift to a great advantage for Metaknight (especially when it has to deal with off-stage business). So, a situation where Metaknight can counter-attack and potentially create a hugely beneficial situation for himself is most likely going to be better than resetting to a neutral position.
Are you generally saying that being able to go from one side of a given stage to the other without a hurtbox is not going to make MK better?
The question is not, "when is it likely that Metaknight is going to use a technique like this to benefit him?" The question is, "when is it likely that Metaknight is going to use a technique to benefit him more than the options he already has?" Since this is going to be used, more or less, to escape certain perilous situations, an aspect of combat that Metaknight's quick aerials and gigantic amounts of priority can already handle for him, then I'm generally saying that this technique will only make Metaknight marginally better, if at all.
For the reasons listed above, I also believe that this is not going to have any significant effect on Metaknight's matchups, either.