Whether you like it or not, it's hard to deny that Omegamon (Ominimon in the English dub) is the starring face of Digimon. He's featured in most of the recent games, having been Nokia's partner in Digimon Story: Cyber Sleuth. In Digimon World: Next Order, he features in the opening act. More recently, he saved the day at the end of Digimon Tri by becoming Omegamon: Merciful Mode. So it's no wonder that it took just two episodes for him to show up in Digimon Adventure: (2020). And while the disappointment that is Tri is its own can of worms to discuss, let's look at why Adventure is proceeding the way it is, and why there could be hope.
Using Tai Brings Nostalgia
When it premiered in the late 1990s, Digimon was part of a trend of studios series involving a male protagonist working with a creature partner of some kind. It competed with the likes of Pokémon, Monster Rancher, and Cardcaptor Sakura. Female lead roles in US children's television were practically nonexistent, as shown by the poor success of attempting to popularize Sailor Moon a few years earlier. Cardcaptor Sakura fans will note that the US Dub was heavily edited to involve Syaoran Li as a main character. The success of a 1990s anime banked on its ability to market its main characters. So when Omegamon came to the scene to defend the world from Diaboromon, it was clear as day who would be the studios permanent cash cow.
It's An Homage to Adventure
That very scene is what appears to have inspired the first two episodes of Digimon Adventure: (2020). The idea of using nostalgia or 'seeing things through nostalgia goggles' often has a negative connotation to it. So is it really a bad thing that Toei is using nostalgia to bring in viewers? If you're watching it, there's a good chance you adored Digimon as a child, and that your favorite part of Digimon: The Movie was the birth of Omegamon. So while some people might be tired of the recent animes being the Tai and Matt show, let's be real, was it ever anything else? We just didn't care because we were nine and wanted to see the fighting.
We Need Everyone
Tri gave some development to the rest of the cast, giving each one its own arc that involved their partner gaining a mega form. In the original Adventure it was only Agumon and Gabumon who made it to mega. So if things go well, the 2020 reboot will combine those elements with the spark of Adventure. The other characters can't possibly be too absent because each one of them brings something important to the group. Joe is the big brother type whose cautious ways bring a balance to the often impulsive Tai. No one can navigate the cyber world like Izzy, he's guided the group through so many trials with his smarts. Sora is always there for everyone, and Mimi's positive attitude keeps the group going. TK and Kari, the group's youngest members protect everyone with their powers of hope and light.
So the answer here appears to be that yes, Toei is banking on nostalgia by once again using Tai as the star. Fortunately times have changed, and there is hope viewers will see other aspects that remind them why they love Digimon.