The eye that Boruto has is clearly not a Byakugan, and everyone can agree, what I find it most likely is a new Dojutsu, no one from the Byakugan family ever married someone with as much chakra as Naruto has, unless you count the grand-son of Kaguya (the dude inside the moon) which already had the Byakugan with an extreme chakra source.
Another option would be the mix of the byakugan with a descendant of the sage of the six paths, but this is denied by the fact that Kaguya never had an eye like that manifested, while she is the original blood of any jutsu, as the creator of the series just said that he forgot to give them Byakugans he may have thought to give Boruto something different, Naruto isn't part of the byakugan bloodline so off-springs that don't have the byakugan are totally possible, the "theory" I like the most is the mix between the Uzumaki genes (the Uzumaki clan) with the Byakugan and the blood of the sage of the six paths, there is no recorded or shown eyes like Boruto's, so a bit of diversity could've been expected from the creator.
Although this looks like a continuation of the Naruto series, it's not really. If you're someone that never watched Naruto you can live happily ever after and have no need to watch it to watch the Boruto series, and even if this was the Byakugan that Boruto inherited it would most likely wouldn't make him have excessive power, he is Naruto's son, not Naruto himself, so he doesn't have the nine tails, and for sure not that much chakra as he has.