It looks like an unexpected issue has arisen just before the release of the Battles of Legend: Monster Mayhem expansion set for the Yu-Gi-Oh! Trading Card Game (TCG).
The Original Announcement

In an X post a couple of days ago, Konami had announced that they would be pushing back the release date for Monster Mayhem in most territories. Konami’s reason was that there was some form of card clumping during the original printing run.
Apparently, the Starlight Rare cards returning in this set had run into a distribution issue. According to Konami, this would result in regions having a disproportionate amount of Starlight Rares than originally intended.
The company added that they would be re-doing the production line for a more consistent release. Because of this, they would need to push back the original release date for the expansion.
Fortunately, this rescheduling would not affect all regions. Unfortunately, at the time of this article’s writing, there hasn’t been a definitive timeline given for the regions that are affected.
Thankfully, this delay isn't affecting every single region. In their X post, Konami stated that English-language cards for Latin America, Canada, and the United States are unaffected by this delay. As such, these regions will still get Battles of Legend: Monster Mayhem on the expected June 13th release date.
This leaves the regions of Europe, Africa, the Middle East, Oceania, and parts of Latin America reliant on Spanish & Portuguese cards, waiting for more news.
Consequences of the Schedule Change
In a follow-up X post, Konami made it known that any new cards to be included in the Battles of Legend: Monster Mayhem set will not be tournament legal for Europe, Africa, the Middle East, and Oceania.
This is a major blow to any players wanting to test or bring decks that make use of any of the new support cards coming in the set. So far, we’ve covered the new P.U.N.K., Orcust, and Gem-Knight cards that are included in Monster Mayhem on this site.
As if that wasn't enough, many more new releases are coming in this set we’ve yet to go over, like Nekroz and Jurrac.
The Yu-Gi-Oh! World Championship is just around the corner, slated for the 29th to the 31st of August.
While a delayed release may not mean much in the grand scheme of things, it’s still less time to test with for players who considered using these more rogue archetypes
Battles of Legend: Monster Mayhem Shine with New Gem-Knight Support