Before I actually get to the point, there's something that needs to be said:
Quote:
Mostly because I want them to make room for flash and seedborn muse to be banned, but also because I don’t know if they deserve the slot anymore.
These two points are as irrelevant as any point can be. The goal of keeping the banned list as short as possible is a general one, not like they're trying to hit a quota or something. While bannings and unbannings do often happen in the same announcement, that's usually more due to the fact that each banning period is relatively long (and in the most recent case, literally a bunch of new members who all had their voices heard). And even then, if anything the pattern is that things don't often get unbanned without a banning to replace it, not the other way around.
Also, Flash and Seedborn Muse will never get banned. The banlist exists to adjudicate EDH, not cEDH, and those cards will never deserve to be banned in EDH.
But, on to the actually relevant points:
Coalition Victory: I think you
vastly underestimate how easy it is to set up. Regarding the lands, virtually every deck is packed to the brim with shocks, fetches, bicycles, slow lands, and OG duals, and almost every deck that can even run it has access to 5 colors in a single creature, one that you have access to the whole game. In other words, all of the setup it requires is stuff you'd already be doing anyway. And while there is no data to speak of how powerful a deck built around it would be, it is literally the most boring and anticlimactic win con in the history of Magic. It cannot impact the board in any way. It cannot interact with your opponents. It isn't even that affected by anything else that has happened in the game. It literally either wins you the game instantly, does absolutely nothing, or gets countered. Those are the only options. It will never do anything else.
Biorhythm: Mentioning
Shaman of Forgotten Ways as a comparison point is as much of a red herring as
Arcanis the Omnipotent is to the legality of
Ancestral Recall. The effect is the same, but everything else is so different that there's no room for comparison.
All that aside, Biorhythm's problem is effectively the same as Coalition Victory, just not as much. It's a win condition that is trivial to set up, and more often than not can just happen as a matter of chance. The one area where it is arguably more problematic than CV is its ability to not win you the game but rather knock out other players. As boring as Coalition Victory is, it makes everyone shuffle up and start a new game. Biorhythm more often than not will knock 2-3 players out and have them sit around while the remaining pair duke it out. Of the cards you mention, it's probably the one that would be the safest to unban, but still far and away not worth it.
Sway of the Stars,
Worldfire: These both are banned for largely the same reasons, so I'll address them together. The first is that they affect life totals, hit everything, and get around almost all anti-removal that isn't named
Ghostway or
Teferi's Protection. This effectively erases everything that happened earlier in the game, making it as though everyone had just wasted their time.
But more importantly, they are almost
never used as a mere game reset. Every deck that runs them will do so with a way to make the reset as asymmetrical as possible. The aforementioned Ghostway and Teferi's Protection are common ways, alongside
Oblivion Ring targeting your own stuff, or just
Jhoira of the Ghitu. But the most common tactic, one that is only possible within this format, is to just float a bunch of mana before the casting, and then cast your commander. This particular tactic was the main reason why Sway (and Upheaval) was originally banned, and the RC rightfully smelled a rat the instant Worldfire was printed as it was effectively the same card but worse.