A confluence of factors could see the Pokémon fighter get a massive push in Los Angeles
http://www.nintendoworldreport.com/editorial/40368/why-pokken-might-be-the-secret-weapon-at-e3
For the last couple of years, Nintendo has had a major tentpole Wii U release at the end of May with major online functionality, DLC plans, and (later) Amiibo support that has set the tone for the entire year. 2014 saw the ludicrously (in Wii U terms) successful Mario Kart 8, and early reports have Splatoon selling out in some locations, most notably nearly selling out the entire first shipment in Japan. This begs the question I posed on the June 1 edition of Nintendo News Report as to what the major game with a full reveal at this E3 would be. It wouldn't hit me until later that Nintendo has a secret weapon being tested right now in Japanese arcades that could potentially fill the bill: Pokkén Tournament. And I'm extremely confident that the home version of Pokkén Tournament will get a reveal at E3, with an eventual release date of May 27, 2016 worldwide.
The previous Pokémon Company policy on game reveals was always to announce the game in Japan and let the other territories come later. However, since Pokémon X/Y were revealed in 2013, every Pokémon game released internationally has been announced simultaneously for all regions, even if the release dates differ (see Pokémon Super Mystery Dungeon). This includes everything from mainline RPGs down to the dreaded Pokémon Shuffle. And since you're talking about the first reveal of a console game, why not do it at an E3 when the eyes of the gaming world are on you? Even Nintendo kind of admitted that E3 was going to be console-heavy when they dropped most of the rest of the 3DS lineup for the year in the Direct Micro earlier this week.

The clamoring for a console Pokémon game has gotten louder with each round of Wii U sales numbers, so clearly the game would be a hot topic at E3. But could a complex fighter be ready for a simultaneous worldwide release by May? Absolutely. Consider that although Pokkén only has seven announced characters, they could easily blow out more at E3 – and the arcade game has been in location testing in Japan for several months now. The release date for the arcade version is set for July, which would leave about 10 months of a rabid fighting game community in Japan banging on the game to determine what needs to be balanced for home release. And we know that Nintendo's not adverse to updating games really quickly, given how the first round of Splatoon content was unlocked within four days of anywhere on the planet starting the game.
The only other thing that could stop this from happening is if they elect to show off the last games of the handheld 6th generation at E3. Traditionally, the reveals for this would fall around mid-month – though earlier when the Japanese magazine CoroCoro leaks three to five days before – and there is a metaphysical certainty that something Pokémon will release on February 27, the 20th anniversary of Red and Green releasing in Japan. If they're going to try and get another generation in before the 3DS is replaced by the new handheld (read: the NX), an E3 announcement for a February 27 release would work. Given the nature of worldwide releases for Pokémon and Nintendo hardware, however, it's far more likely that the RPG is going to be the expanded version of Pokémon X/Y. Those usually have a shorter lead time between reveal and release, generally about six months, which lends itself to a reveal at the 2015 World Pokémon Championships in Boston in mid-August.
There are a lot of things people are expecting out of Nintendo this year at E3, but Pokkén seems to have slipped under the radar. Maybe it's the fact that the game's just an arcade game, who knows. But I know I want to see Saturyne the Hawlucha make her console debut as soon as possible, so if it does get revealed at E3, my apartment's going to be a one-man recreation of the Twilight Princess reveal.