Seems very unlikely that a sheet went out with this error and for only the Pikachu to be seen on socials with all the hype around the set.
Currently all being auctioned from one seller
calebscardsandcollectibles
It seems plausible to me that this could happen, but it’s always good to maintain a healthy cynicism towards these sorts of errors. Especially with the ways things are currently.
These kind of errors have occurred before in other sets (see edit below), and five of them from the same seller isn’t too odd, since cards from one uncut sheets usually end up in multiple booster packs of the same booster box. 
Besides, this set has a lot of errors already. Not too surprising, when literal millions have been printed due to high demand. I’m glad TPCi for a change seems to have printed by demand, even though a lot of stores still lacks products tbch.
Here some more crazy errors from this set: https://www.instagram.com/p/DdmpXFSDnID
I do agree it’s good to have skepticism, since fakes seems to occur more often and are less distinguishable these days, especially for high value cards. But I personally don’t see anything wrong with these error cards tbh.
EDIT: Here some examples I’ve saved of similar errors in various of sets/languages:
Someone once opened an entire Mewtwo Mayhem XY Evo theme deck like that, with all 59 non-holos as this error. Here two of them, and I own a Gastly myself:
And here some random other ones I’ve saved pictures of:
Greetz,
Quuador
hello factory smuggling my old friend
