Ending credits analysis theory
Fan Theory-1:
The visuals are strange. Lots of people smiling and looking generally happy, it didn't give the impression that these were the people Goku is going to be removing from existence. If anything I got the vibe that they were almost rooting for him....
Here is the ending for reference:
Pause at 7 seconds in.
The Universe 4 spy, Cabba, Caulifla... even Frost. They don't look like the enemies.... I'm still banking on a split occurring during the tournament where there is a divide and some people side with Goku and co. I could be wrong but that's the vibe I'm getting and have had from the very start.
The next scene with the other warriors gives me the impression that they will be the threats going forward, culminating with Toppo, Dyspo and of course Jiren being the end goal of the battle.
Jiren's eyes flashing is incredibly ominous. He makes me feel more uneasy than any DB character I've encountered so far. We've been told so little about him, I think it's setting him up to be more than just an average opponent. Is he a God, is he evil? I believe we're going to be in for a surprise or potentially a nasty shock when we learn more about him.
The next scene where images of Goten/Chi-Chi/Gohan/Videl are displayed is clearly the thoughts going through Goku's mind. The people and lives he is fighting to save. If you look carefully there are cogs turning in the background of this particular shot and this is to signify Goku's mind working as he remembers just what is at stake. Very clever imagery. Also if you notice carefully the images fade out and appear in his eye, signifying that these are indeed his thoughts.
He's clearly wounded, standing on his own. Until Gohan appears next to him. I think this is signifying Gohan will be with his Dad fighting by his side in this until the bitter, bitter end, no matter what.
The rest of the team is standing behind them, looking on. I think this is telling us that they will all be eliminated at some point, leaving Goku and Gohan to finish the battle.
I love analysing these ending credits for imagery, there are lots of little clues if you look hard enough.
Fan theory-2:
The start is Goku in a ruined city or something at night, the song essentially saying: "if the signal of farewell rings out, I will think of you". The scene represents the fighters in a despair filled scenario, specifically, the fighters are worried about annihilation. The song seems to be referring to Goku.
The next part is the showcase of what seems to be the major enemies in the arc, ending with Jiren, Toppo and Dyspo very ominously shown in front of blue fire, which generally is generally used to symbolized something unnatural or great destruction. Meanwhile, the song says "who will go so far someday", in reference to the "you" which seems to be Goku, presumably either saying Goku has great power and can do great and awesome things, or that one day he will die and go to Other World or "far away".
Next is the part with the gears. We see the 4-Star Ball, Goku's favorite and a cherished object as a child, and we see the family he lives with (Goten and Chi-Chi) along with his son's family (Gohan, Videl, and Pan). As this goes on, the song says "I watched you from your left / I looked at the side of your face" Next we get Goku damaged, but still fighting. Persisting through the tournament, never yielding. Gohan steps up and Goku is surprised, but then they both smile and turn back forwards towards the sun, which may be the future (a new dawn after the dark night that was the tournament), which could mean Goku is surprised by Gohan's attitude after they had somewhat of a disconnect ever since Gohan started having a family, but they're both happy to take on what lies ahead together. The song goes " Were you laughing or were you crying? / Your long hair was in the way." The song's narrator/POV seems to be Gohan, talking about how he looks up to his father and will never forget him, even if he leaves. He's always been watching his father, but he's always been watching from the outside, and therefore he has never been able to truly know him. Hence "were you laughing or crying". Two opposite emotions, but with out having the right perspective could be hard to tell apart. The ties in with Goku looking surprised, because Gohan was always on the sidelines or vice versa. Every arc has one out of commission (or watching from the ring side, with Cell) while the other is fighting.
Next, we see the other members of Universe 7, including Freeza, also looking out into the sunset. It ends with Goku and Gohan dashing forwards into the sunset, or the future. The song says "If the signal of farewell rings in the night sky / It will shine an eternal light / On the path of our weak selves someday / So that we may meet again". If Goku leaves, then one day, the Goku and Gohan, two insignificant specks in a universe with gods of creation and destruction, and angels and an all powerful God-King, will one day meet again.
I basically see the outro animation as being Goku and co fighting through the tournament of power as their darkest night, and emerging on the dawn of a new day or era, heading to the future, with Goku and his son standing together as equals in this new future. The song has Gohan's perspective of his father, always looking up to him, and if they part ways, they won't stop thinking about each other and will one day meet back up; that they're bond won't break, no matter what.