This gift was distributed via Serial Code to players who preordered the movie tickets to M22: Mewtwo's Counterattack Evolution in Japan.
This gift comes with 200 in every AV stat. Additionally 3 out of 6 IV stat are 31, and the rest have the value of 30.
The Trainer ID signifies the date of M01: Mewtwo Strikes Back's first release in Japan: July 18th, 1998.
* Interestingly, there are bitflags that indicates that 2 additional (unknown) games are eligible to receive this wonder card. Maybe they're testing it on Sword & Shield?
(Note: The event redemption period ends before Sword & Shield is released, though)
Thanks @wo0ts for his contribution!
Format Ver.1.0.7-0, Post Updated Date:20190425_0658
What can be done with these files
PKM creation with PKHeX (drag & drop the wondercard file in the spot where you want the Pokémon)
In-Game Mystery Gift redemption with Switch Gift Data Manager