Finally we see some changes on the Tier List! Gaia got promoted to Tier 2 due to having a relatively good matchup spread across the meta and the utility to use powerful cards like Loading... in a 20-card deck. Additionally, Tech Genus got promoted to Tier 3, not only was this deck used during the final Stage of the KCGT, we also saw multiple top players using this deck but it has been lately really successful in tournaments and leagues.
Aside from that we had several rogue decks doing well in the KCGT like Cyber Dragons and Lunalight. The KCGT Top Cut had even more fringe decks like Hero Flash!! Stall, Vampires and Mayakashi due to their special format with a shared card pool across three decks. These decks could possibly be successful in Side Deck format as well, so be aware!
Even without a new box being released into the game yet the meta is experiencing changes during this Onomat-dominated format. While the only changes to the Tier List are Gaia being promoted and T.G. being added, this still adds room for rogue decks to have proper places in the meta. Cyber Dragon is still a powerful high-roll deck that has favorable matchups against Tech Genus and Gaia. There are other rogue decks that can also beat these new additions which may see a rise in play and influence Main and Side deck choices throughout meta decks.
Tier 1
With projections on the new Mini BOX not looking too great (barring some insane Chronomaly Skill that propels them onto the Tier List), it's expected that Onomat will remain at the forefront of this meta until the introduction of Arc-V world. As far as deckbuilding trends go, players have been shifting away from the package of Loading... , Loading... and Loading... in order to slot more tech cards in both the Main and Extra Deck. We will have to see if the slightly increased diversity of non-Onomat decks in the format will spread the Onomat tech slots thin enough to shake up the meta considerably, but we should expect Onomat to continue its reign for the upcoming month.
Tier 2
TPC Comments
Gaia finally moves up to a long-overdue Tier 2 position. While its matchup against Onomat is horrible if they're using Loading... , it gets slightly more interesting if they aren't (albeit still unfavorable since Loading... won't stay on the field very long due to Loading... ). To try and beat the lone Tier 1 deck Gaia, decks have started to play more Trap Cards such as Loading... and Loading... over Loading... and Loading... , which are less useful against a Turn 1 Loading... . The goal for the Trap-oriented shift is to grind down the Onomat player instead of trying to attack through it. It boasts strong-to-neutral matchups against the rest of the tiered decks, which is why I feel Tier 2 is appropriate. I believe there are some rogue decks that can gives Gaia trouble such as Cyber Dragon (which maintains good-to-ok matchups against other decks), which should start seeing usage again unless Konami decides to end it completely.