As of today, Toywiz has sent out a notice for all people that pre-ordered the 4th Dimension Luna plushie stating that their accounts have been refunded. She and a few other background and princess ponies were added to various non-official websites early last year, but outside of a tweet in 2014, no news has arisen involving their actual confirmed release.
We are still waiting for a response from our contact at 4DE on what the status of their lineup currently is. I'll get an update once we have something more concrete to post.
Until then, you can find the actual Toywiz message below.
Toywiz cancellation response:
Dear Valued Customer,This email is in regards to your order for the My Little Pony Friendship is Magic Princess Luna 15" Plush. Unfortunately our order from the distributor has been canceled and we will no longer be receiving this item, as they are no longer going to be making this item.We apologize but we will have to cancel your order for it. If you paid via credit card, as this was a pre-order, no charges have occurred. If you paid via PayPal you will be refunded.If you have additional items on your order, please let us know if you would like to proceed with the available items, or if you would like them canceled as well.We apologize for any inconvenience this may cause, and we would like to offer you 10% off your next order with us.
Thanks to Ronald for the heads up!