Conceptually, I like how these classes are very tied to FR specifically. That's a wonderful bit of design kit and it's something I hope to see more of - classes that evoke some local flavor.
Specifically, my biggest gripe is about the Purple Dragon Knight.
Maybe this is a hot take but I really couldn’t care less that it’s a retcon. If you’ve got a subclass called “purple dragon knight” and it’s something other than a knight with a purple dragon, you’ve messed up. If fixing that requires retconning lore only a tiny fraction of the people playing the game have even heard of, there’s no question that retconning it is the correct choice.
This is backwards.
If what you want is a class option that is evocative of a setting, forcing the setting to conform to an outsider's idea of what it
should be is actually erasing what the setting
actually is. It's giving colonial vibes.
There's a thing in FR called a purple dragon knight. It is cool on its own - an elite military commander, belonging to an order of legendary dragon-slayers (the purple dragon in question was an ancient black dragon whose scales turned violet). It has a good story and has even had some pretty interesting mechanics over the years, driven by realizing ther fantasy of an elite military commander. That's a good fantasy, and one that 2024 Fighters could certainly be better at realizing.
It's not a dragon-tamer. That's not a purple dragon knight. That's something different.
If the purple dragon knight isn't cool enough to be a subclass based on its own lore, then don't use the name. Don't gut the concept and pretend it's an upgrade.
What I
want out of a PDK subclass is a Fighter who makes a good military commander - inspiring, supportive, granting courage and hope enough to turn the tide of a battle.
If you wanted a Middle-Earth setting, you wouldn't give Gandalf a Hogwarts House just because that's something that a general audience thinks wizards should have. If you wanted a world based on The Last Airbender, you wouldn't say that the Air Nomads were a tribe of bloodthirsty headhunters just because it is more exciting than a group of monastic ascetics. Words have meanings, and "purple dragon knight" doesn't MEAN this thing in the UA.
There are a few other features that make me curious, like the quantity and combat focus for Knowledge cleric spells, but this mangling of the PDK is the most concerning to me, because it speaks to a very...2008...kind of perspective, where the words are just there to steal and repurpose for whatever the designer thinks is neat.
I'd love a dragon-knight kind of class. It's a cool idea. It's not a Purple Dragon Knight, though. These are two different things.