Bethesda have certainly taken controversial steps in the development of Fallout 76, such as retconning Brotherhood of Steel in order to make an appearance and having no human NPCs. Now, they confirmed the iconic Dogmeat will be missing.
In Fallout universe, Dogmeat is either an immortal entity that can traverse great distances and change appearance, or simply the same name that was given to several dogs over the course of Fallout, Fallout 2, Fallout 3, Fallout 4 and Fallout Shelter.
Therefore, this companion is quite iconic, but since Fallout 76 will be a multiplayer game, with no companions other than those that are human, the question about the possibility of having Dogmeat around started being asked. Such was the case during Bethesda's panel at PAX Australia while Pete Hines was talking about the game.
He confirmed that there will be no animal companions in Fallout 76, which prompted booing from the audience according to Gamespot. Hines quickly reacted by stating that dog companions would be added to the list of features that Bethesda might consider for a future update, although nothing is set in stone.
To be fair to Bethesda, this isn't the first time Dogmeat was missing from a Fallout game since the company took over the IP. Fallout: New Vegas was developed by Obsidian Entertainment, it was a singleplayer game and was praised left and right. It had every possibility of including Dogmeat to the companion roster, but Obsidian chose the cybernetic dog, Rex.
With focus on multiplayer in Fallout 76, lack of dog or any AI controlled companions was to be expected, but there are definitely fans around the world that will miss the loyal furball.
Fallout 76 will not have mods or dedicated servers until at least November 2019, so it's safe to assume that Bethesda's schedule for the game is filled up for the next year. Therefore, if a dog companion does happen in the future, fans will have to wait quite a while before they do appear.