Hmm...I guess. But we don't know for sure it does involve the MetaNav. Remember what she said? "someone got something back".

[Mementos wasn't a "Something", it was a "somewhere". Elliot didn't have reason to suspect Goro, but it was important not to get too fixated on details not yet proven.]

I understand the feeling. People act like it's obvious that someone would use their regained powers for murder but...it's still scary to think about.

[People were dying, and that had to be stopped]

...If anyone could hack in, it'd be 'Taba.