This new tournament being announced made me wonder if the previous Japan-only tournament showed up on the Japanese website. I thought that these type of tournaments were possibly the events that began with 3, but I looked it over at
https://www-aaaba-lp1-hac.cdn.nintendo.net/ja/index.html and couldn't find it anywhere.
By the way, looking at the first Twitter announcement, these new type of tournaments are distinctly called オンラインチャレンジ (Online Challenge) instead of トーナメント (Tournament). The Mario-themed tournament was called this in the Japanese stream of the Mario 35th anniversary direct, so it seems like it'll be another one of these special tournaments. Fun fact, Yuichi Nakamura, voice actor of Jojo's Bruno Bucciarati, narrates the Japanese Directs.
I considered that the Mario tournament could have been the skipped Tournament Event, but the fact that it's part of these "Online Challenges" means that it's not going to be numbered like the other Tournaments we've had, so that provides more evidence that the skipped Tournament
potentially features the next character and that this skipped Event is not the Mario tournament.
There were 11 days between the News Events that were pushed forward and the Min Min announcement, so I'm expecting a new character announcement in less than 2 weeks. That is of course, if the skipped tournament is in fact the one that accompanies every new character.