One of the best features introduced in is the newly introduced immersive cards. These special collectibles contain unique animated artwork exclusive to and are highly sought after by players everywhere due to their rarity and special illustrations.
Currently, only four immersive cards exist in the game: Pikachu, Charizard, Mewtwo, and a secret Mew card. With the recent announcement of more booster packs releasing later this year, many players hope that later generations will get more of a focus.
The most logical step would be a heavy focus on Generation 2, as it contains many Pokémon that are incredibly popular to this day.
Even with all the available options, it is likely that only a very select few will actually be selected. Since Mewtwo was selected to be one of the few Pokémon to receive an immersive card, it only seems right that one of the Johto Legendaries gets one, too.
Both Ho-oh and Lugia are incredibly popular, but between the two box art Legendaries, Ho-oh seems like the likelier candidate.