Summary
Magic: the Gatheringhas taken yet another step in integrating Universes Beyond into the game at large. Now, these crossover sets will not have a unique frame, and will instead look like any in-Multiverse MTG card.
This will come into effect from theSpider-Manset onwards. This means that theupcoming Final Fantasy crossoverwill be the last Universes Beyond set to use this unique frame, as that is going to release this June, with the Spider-Man cards coming later in the year.

Magic: The Gathering Is Ditching The Universes Beyond Frames
Crossover sets will use the same frame as non-UB MTG cards going forward
This was revealed in ablog postearlier today, giving us some details on the upcoming Spider-Man series.
“As part of our continued efforts to reduce complexity, we are retiring the Universes Beyond frame and unifying all Magic: The Gathering frames within the standard Magic style,” the post reads. “Eagle-eyed fans out there will notice that, starting with Magic: The Gathering | Marvel’s Spider-Man, Universes Beyond cards will no longer have the inverted triangle replacing the standard oval security stamp for rare and mythic rare cards, as well as the stamp printed in silver on common and uncommon Universes Beyond cards.”

The Spider-Man set is launching on September 26, andthe first six cards were revealed earlier today.
This isn’t overly surprising, given recent moves with UB sets. As of this year,UB releases are legal in every format, whereas they were previously excluded. This won’t affect the previous UB runs, like The Lord of the Rings, but it will come into effect as of the Final Fantasy set, and then stay in place for all releases going forward.
It’s easy to see why MTG is making these moves.UB sets are consistently outselling their in-Muliverse counterparts, so it makes sense to simplify everything for the new players that the sets bring in. It also means we can expect many more UB sets, witha SpongeBob SquarePants crossover already confirmedfor later this year.