US consumer mentality is just ridiculous sometimes. There is NO reason everyone who bought the season pass should automatically be treated the same as people buying the Ultimate Edition now. Earlier adopters got exactly what they paid for, at the price they decided was acceptable to them, and have been able to enjoy the game for all this time. There is no further obligation implied.
Bethesda doing more with Doom Eternal is great goodwill, but it does not obligate any other company to bend over backwards and do the same.
What a time we live in. "High outrage" ( ) should not be a reason for companies everywhere to give more and more shit away for free.
Giving the base game a free upgrade might make people continue to play it and want to buy the DLC. Locking the upgrade behind a full re-purchase of the game is going to turn away pretty much anyone who already gave them any money. It's not the same as people asking for a free remaster of a game that is many years old.