The Emissaries were those guys who were constantly switching between different team's costumes. They were eventually basically revealed to be the "middlemen" for the Morphin Masters. Like...if the Morphin Masters are "gods", then the Emissaries are their "archangels". They actually have some interesting lore to them, since they're the first people to access the Morphin Grid to actually become Power Rangers..in Earth's distant past, but that's a story of it's own.
And, well, I've talked about it before, but the comics, for all the hoopla about wanting to be "canon", are basically a splinter timeline.
Hasbro has done this for MMPR episodes recently. When I had cable I saw Dark Wish uncut as a TV movie of sorts that week. Mid way through Mystic Force it swapped over to ABC Kids. I watched MMPR - Space Patrol Delta on DVD as I didn't have cable at the time they were on the air. I came into...
www.allspark.com
They're "canon" in the same way that RPM and Dino Charge are canon. Different universes, but close enough to pass a squint test. The stuff in the original era of Boom comics can't really fit with the rest of what happened in the main show timeline. Even though, they kind of tried to make it work.
And, recently, the Boom comics have REALLY been embracing the "alternate timeline" stuff. Almost everything they've been doing has been some form of alternate future for the franchise. Right now, we have 3 ongoings going on at the same time. And all 3 take place in different "what if" variants of the timeline. The main "Mighty Morphin" book is set in the..."slight alternate past of the present" with aged up versions of the original cast, but set before Trini died. PR Green is set in a post-apocalyptic future with Tommy trying to take care of a alien girl. And Unlimited is a massive constant crossover with every single Ranger team going on missions together.
...It DOES kind of feel like they're throwing everything they can think of at the wall to see what sticks. I kind of wonder if Hasbro is having them brainstorm and pitch things on purpose, just to find SOMETHING that works for them. So, we'll see what they end up landing on.