IMHO this is Canon in Fallout 4

[WeyounDS9]

Canon not that he joins the Brotherhood, but when he returns to his old house Sanctuary his state of mind in the last scenes.;
SPOILERS, if you have not played FO4 consider not watching!

 

[Rand]

Spoiler alert
Fallout 3 story.. in 3 you can be everything to everyone.

fallout 4 .. pick a fraction. YOU MUST PICK A SIDE.. and iirc destroy another fraction totally, and possibly a second or 3rd



I picked the minutemen because its the best ending IMO. Although there are no real good options.. "cant we all be friends" resolution.
It was bad that you have to destroy the most advanced fraction that could help the world heal from the post nuclear apocalypse

 

[WeyounDS9]

Spoiler alert
Fallout 3 story.. in 3 you can be everything to everyone.

fallout 4 .. pick a fraction. YOU MUST PICK A SIDE.. and iirc destroy another fraction totally, and possibly a second or 3rd



I picked the minutemen because its the best ending IMO. Although there are no real good options.. "cant we all be friends" resolution.
It was bad that you have to destroy the most advanced fraction that could help the world heal from the post nuclear apocalypse

Yes.
None of the standard endings would mean happiness for the Sole Survivor.
In my mind the only way he can find happiness is this:

Christmas morning magazine Cover in the Commonwealth, years after the events of FO4:
https://staticdelivery.nexusmods.com/images/1151/59691286-1734198780.png

 

[KrisZ]

I don't really understand this fascination with "cannon" because that in and of itself is highly subjective and changes all the time.
And then you have oxymoron like open endings. I just enjoy the game on its own merits and not how it ties back to its predecessors.

But we have a TV series now, so I have a feeling all this "cannon" talk is just the IP owners trying to create yet another "universe" IMO.

 

[WeyounDS9]

And also this happy ending:

https://staticdelivery.nexusmods.com/images/1151/59691286-1734198780.png