In an exclusive interview with US Gamer, the developers behind the upcoming port of Doom 64, Nightdive Studios announced that the game will come packed with a brand new chapter when it releases on March 20. When asked about possible connection connections to previous games in the franchise, James Haley, the senior developer at Nightdive, provided some insight. "On our end, persistent players will have the opportunity to unlock a new chapter in the Doomguy's saga, taking place shortly after [Doom 64's] original campaign concludes, " Haley states. "The Mother Demon you defeated in that outing had a sister, and since you've been messing up Hell non-stop, she tries to get rid of you by sending you away. If you can make your way back and take revenge, you’ll be rewarded with a bit of lore that fans of both series, new and classic, should enjoy." We don't know what the "lore" that James Haley is referring to, but it's possible that it could have something to do with the popular fan theory that connects every Doom game.
Samuel Villarreal, the lead engine developer, also explained during the interview that they also managed to clean up some of the bugs that were in the original game. "There were a few bugs that were addressed in Doom 64," Villareal says, "such as a check to prevent spechits overflow and checks to prevent Lost Souls from getting ejected out of the level when Pain Elementals explode. There were also some changes to the collision system that resulted in new bugs such as getting caught in 90-degree corners. These collision changes also prevent the speed boost trick when running up along northern angled walls."
Bethesda received backlash when they re-released Doom 1, 2 and 3 in 2019 as players were forced to create a Bethesda account to play the games, but luckily the developers quickly patched this issue out. The port seems to be in good hands with Nightdive Studios who are known for publishing a huge array of re-releases that include, Turok 2: Seeds of Evil, System Shock: Classic and Sid Meier's Pirates! Gold Plus. They are also currently developing the remake of System Shock which is releasing sometime in 2020.
Doom 64 will see a release on the PlayStation 4, Xbox One, and the Nintendo Switch the same day that Doom Eternal comes out.