Unfortunately, Warner Brothers lost those files. Rumor has it when they sent copies to Sierra (really Vivendi at the time, just before the Activision acquisition) for a Babylon 5 videogame the WB Archives team accidentally sent their only copy and that when the videogame project was shutdown they destroyed the copies per the IP license agreement.
There's a high probability that even if WB had had the digital masters of the effects, they probably still would have stuck to the 4:3 restoration over the 16:9 restoration to avoid recompositing costs, but it's still such a weird swing of bad luck that the production team thought ahead about HD technology well enough as well as anyone could at that time and yet the 4K copy we have in this timeline is in the wrong aspect ratio.
In 4:3 it looks good and like the original airing show, in 16:9 any non-digital/composite shot looks freaking fantastic. But once you get to any digital or composite shot it takes a nose dive in quality.
https://www.modeemi.fi/~leopold/Babylon5/DVD/DVDTransfer.htm...
I have these versions, and it's world better than everything beforehand. It's also a good opportunity for a re-watch!
Sheridan was maybe a bit cheesy at times but definitely gave off that vibe of a leader one could follow into battle.
If you want to pirate it, with yt-dlp and the URL, you can download items from the Tubi web site. (Don't ask me how I know.)