It's not a "new" format. The quick listing tool has been around for several years. It's just that most of us have always used the advanced tool. Most newer sellers who started selling after the implementation of the quick lister don't know there's another option, that's why there's often confusion when questions are asked about listing, screenshots are posted and the OP can't see anything resembling the screenshot.

Every now and then there's been a glitch and I've been reverted back, but I just changed back using the link at the top of the listing page. I also changed back to the quick lister last year or whenever it was when the 3 free relists were removed from nearly everyone. They still appeared on the quick lister. Then when it was restored in advanced, I went and changed them all back.

If I create a new listing, rather than sell similar, it automatically takes me to the quick lister (it's very rare I create a new listing, almost always use sell similar).