The Pokémon Trading Card Game expansion set "Aura Seekers," scheduled for release in 2027, may include Mega Diancie ex and Floatzel ex. This information has not yet been officially confirmed.
Unconfirmed reports from PokeBeach indicate that if Mega Diancie ex is ultimately added, it will join Mega Absol Z, Mega Lucario Z, and Mega Garchomp Z, already listed in the lineup, bringing the total number of known Mega Pokémon ex cards in "Aura Seekers" to four. Floatzel may also receive an ex card, but not in its Mega Evolved form.
"Aura Seekers" follows this week's release of "Delta Reign," the sixth expansion pack in the current Mega Evolution series. The Pokémon Company has also planned another expansion set called "Mega × Mega Parade," but has not yet announced which Pokémon will be included.
According to PokeBeach, there are still 16 Mega Evolved Pokémon that have not received their own trading cards, including Mega Banette, Mega Pinsir, Mega Victreebel, and Mega Chesnaught. Based on the current roster, the media speculates that if "Mega × Mega Parade" does not significantly increase the usual number of included Mega Pokémon, it may not be able to cover all candidates; this judgment is not an official elimination list or release commitment.