Technically yes but it's not like the WOTC police are going to raid your off Wednesday session and steal your books.
The reason they want it that way is so people know that they can go into a participating store on Wednesday and play Encounters.
@feetz_grande on Twitter
Yeah that's how I figured it but the store owner flat out said no as if WotC would actually do something. Ah well, guess we just have to hold the "off" sessions somewhere else.
Since we're going to stop running the official Encounters adventures that will allow us more time with LotCS. Skipping a week won't hurt us.
Yea, if the owner is stifiling the game then I think you're more than justified in going somewhere else if the players want to.