A few months ago, a Pokemon Sword and Shield leak reared its head, claiming there would be 90+ new Pokemon, no regional variants or Megas, the enemy team were industrialists, a train travel system, and more. It's pretty clear that the "leak" has been rather hit-and-miss, as Galarian Pokemon were revealed not too long ago, but the lack of Mega Pokemon is spot-on. Moreover, neither Team Yell nor the also-leaked Codex Organization appear to be various industrious, but it was right about the train.
Pokemon Sword and Shield's developer Game Freak recently revealed a new trailer that took fans on a tour of an unnamed town. This town has a Pokemon Research Lab, a Pokemon Center, a boutique, a produce store, and the aforementioned train station. Game Freak's Shigeru Ohmori walks players through the town and showcases Professor Magnolia at one point.
The Pokemon Research Lab and Professor Magnolia seem to imply that this is the town where players will begin, with perhaps Magnolia giving the trainer their first Gen 8 starter Pokemon. That said, there seems to be a lot of research involved with what we know about Pokemon Sword and Shield, so it's possible that this isn't necessarily the case. The train station appears about halfway through the town tour.
Notably, Ohmori states the train is used for commuting and for pleasure, but while a train ride through the country does sound pleasurable, that may not be the exact meaning, if the aforementioned leak is any indication. Alongside the train's existence, the leak also states that it is similar to the Battle Subway in Black and White, with players able to use the train for "travel" or "battle." We know that trains exist now, confirming that part of the leak, but exactly how accurate it is in this detail is up in the air.
Ultimately, it remains to be seen, but given the prior inaccuracies of this Pokemon Sword and Shield leak, fans should take it with a grain of salt until Game Freak officially confirms the ability to not just travel, but battle, on the train.
Pokemon Sword and Shield releases on November 15, exclusively for the Nintendo Switch.