This theory doesn't hold much water, and there are a couple of simple reasons for it without even needing to dig heavily into 1.0 lore.

1) Yoshi has confirmed himself that Louis tucked us away in a pocket dimension for 5 years in order to avoid the calamity. You would have to believe that Yoshi himself would lie about this, and you know how he is about lying and following through with promises.

2) Whether 1.0 was witnessed with the Echo or firsthand, either way our characters and we as players don't get to witness the past 5 years and have to fill in the gaps ourselves. So what's the benefit of saying it was the Echo? All that means to us as players is that it cheapens the entire experience of 1.0. Oh, sorry, that whole thing was just the Echo so even though it all seemed to matter pretty much everything you did couldn't change the past anyways. From a storytelling standpoint, it's a huge copout and a giant disservice to loyal 1.0 players. Yoshi even said himself in an interview that one of his goals since taking over was to make the individual player feel more important to the story.