@sol1056 has a great theory - three anons: what the hell was all that in S7 (link below) - in which Season 8′s original ending - Allura getting Atlas - was switched with Shiro getting Atlas in Season 7, so Keith has a full arc as the Black Paladin since he didn’t get one, thanks to the Operation Kuron subplot. (This would also bring into account the cut-and-paste job with Shiro in the first few episodes, since “A Little Adventure” might have been set as the S7 midpoint, empowering Shiro to step into the Black Paladin role by the end of Season 7.)
This falls well into Janestrider’s recent meta, where Shiro was injured fighting the pilots in “The Road Home.”
So…the only reason I can come up with, is that the EPs fought hard to get Keith his proper leadership season, to the detriment of the overall lore and character arcs, including Lance and Blue making up, Allura regaining her command role, and Keith reconnecting with Red.
It also sets back the entire team because - if Shiro could teleport, then Keith could wield fire, Lance water, Pidge forestry, and Hunk rocks.
We’d have the Guardian Spirits of [Element].
Instead, Keith can fly Black, Lance will probably never embrace his own strengths, and Allura will never achieve the command position she deserves.
And Shiro? He currently doesn’t even have a family, let alone a lion.
This story went from a space epic to a space tragedy - all in one season.