There's been a lot of explaining going on when it comes to The Last Jedi. Rian Johnson has been out promoting the movie while explaining some of the decisions that he made to satisfy Star Wars fans' quest to learn everything about the movie, inside and out. However, a lot of the questions about plot holes have been answered elsewhere, including The Last Jedi: Visual Dictionary and more recently, some DLC from the Star Wars: Battlefront 2 video game, which has settled the Dreadnaught debate from the opening of Rian Johnson's movie. There are SPOILERS ahead for The Last Jedi as well as Battlefront 2, so read at your own risk.
One of the biggest plot holes in The Last Jedi comes straight away. Several Star Wars fans have asked how Poe and his fleet knew exactly how to take out the First Order's Dreadnaught with their strategic bombing. It's a valid question, and it's been answered by the recently released DLC for the Battlefront II video game. In the latest mission that is available for free to anybody who has purchased the game, the Resurrection DLC contains content revealing how Imperial commander Iden Versio, her daughter Zay, and Shriv Suurgav obtained the plans to the Dreadnought and transferred them to General Leia Organa to help the Resistance. Obviously, those plans helped Poe and the Resistance bombers figure out where to deploy their bombs.
It has also been hinted that those plans were also responsible for Finn and Rose getting on to Snoke's ship undetected to disable the hyperdrive tracking. However, this isn't explicitly stated in the game like Poe and General Organa's mission is, so maybe some more DLC will go on to prove that to be true at a later time. The main storyline of the game also shows how Luke Skywalker obtained the Jedi compass that led him to his exile on Ahch-To. The compass is briefly seen in The Last Jedi in Luke's hut.
The Star Wars: Battlefront II video game was set up to launch right before The Last Jedi and it was advertised to be connected to the movie. Many fans theorized that the game was going to reveal the true identity of Rey's parents, which the game played off of, going as far as to name Iden Versio's daughter Zay in a clever curve ball. Instead, the game has been loosely attached to the movie, tying up little plot holes for fans that care to play through the game. There's not a whole lot of meat to the campaign section of Battlefront II, but it does get a little more interesting with the addition of the DLC.
There will be more DLC released for Star Wars: Battlefront II this year, but is unclear when it will be released as well as if it will have any more connections to The Last Jedi. For now, fans looking to get some more questions answered about the movie should check out Last Jedi Visual Dictionary and give Battlefront II a shot for some of the smaller loop holes. You can check out a video describing the connections from The Last Jedi to Battlefront II below, courtesy of The Star Wars YouTube channel.