In some ways, WWE is a bit like a magic show. Pretty much everyone in the audience knows that what they are seeing isn't real, but the performers on stage (or, in this case, in the ring) still have a duty to their profession to hide the tricks of the trade through sleight of hand.
In the squared circle, however, this is much more difficult to do. Wrestlers don't get suspiciously long sleeves from which they can pull out doves, or a doppelganger hiding just behind their curtain who can take their place at the other end of a door.
Combine that with the advent of the internet - where any failed attempt to disguise obvious fakery is captured in slow-motion and laughed at by thousands on Reddit - and it's more or less impossible for WWE to keep their secrets from the public domain.
Perhaps it's not such a bad thing, though. Knowing all this stuff actually gives you a renewed appreciation for the deft skill that goes into producing a compelling wrestling match - even if it also sometimes kills the unpredictability too.