Last week Bethesda announced that a "Season Pass style system" was coming to Fallout 76 this summer, which would introduce new progression features, ranks, and rewards. There were concerns from players, however, due to the wording of Bethesda's unveiling of the seasons system.
The new Fallout 76 roadmap laid out the upcoming summer, fall, and winter seasons, with Bethesda's post stating all players would be able to "take part in our inaugural Summer Season for free." Some players inferred that the wording could mean the fall and winter seasons might not be free, but today Bethesda confirmed that, yes, all seasons are free for everyone.
To clarify, our Seasons in Fallout 76 are going to be free for all our players. We may add extra Fallout 1st bonus rewards in the future, but want to focus on getting Season 1 in game first and seeing your thoughts. Sorry for confusion on this.May 20, 2020
Why it took six days to issue a simple clarification and clear up the confusion, I don't know. But at least we now know for sure that Fallout 76's season pass isn't going to cost anything extra for players.