Ubers if I remember correctly include all legendary pokemon by default... even when they stink. Though it only strongly affects one pokemon (Some Ice/Dragon type before it got its hybrid forms)
Cover legendaries, probably, but even then, base Kyurem (the Ice/Dragon you recall, though to be fair, it wasn't a cover legendary until it received its new forms) isn't Uber. Of the cute legendaries being mentioned, only one ever made it to Uber (Manaphy, Gen 4-5). Uber isn't a rarity guide; it's a power rating (along with the BL/Borderline tiers and AG/Anything Goes; typical Smogon tiers are based on usage) by an unofficial group (albeit an influential one in the English meta). That said, Nintendo's ban lists frequently do extend to all legendaries regardless of ability, so that is likely what you're thinking of.
Also, come join the dark side. Buy at release. We have cookies. :3
I miss third-version releases as well.A friend of mine has been harping on me to try to make a dragon only team for triples. Me and him used to make themed teams all the time but while I wouldn't call it a rut, I have kinda been stuck in a particularly effective team that includes grass/fire pledge, a sunny day, an aerodactyl that only exists for sky drop, wide guard, and taunt, some Zoroark shinanigans, and a rhyperior with an assault vest.
I haven't used a real dragon type since fairy was introduced. Pretty much finding them to be far too short lived now. Have there been any interesting changes to any dragon types I should look into since Black and White that folks are aware of?
At any rate, Gen 6 dragons. Not much has changed move-wise; no new moves were added to the type for the first time...ever, really. Most notable in their base form are the uniquely-typed Dragalge, Tyrantrum for its design, Noivern for its speed, and Goodra for special bulk. Dragalge's Poison/Dragon type helps reduce its vulnerability to Fairy attacks and its special bulk compares favorably to most Fairies, but it is quite slow and its offensive ability is mediocre. Tyrantrum is a T-rex, but the King of Lizards is not quite so regal when it's shackled to a Rock typing and a mediocre speed; Dragon Dance still makes it usable, and Rock does give STAB to some good offensive options. Noivern is fast and flexible for both support (Tailwind in Doubles, Taunt in general) and offense, and does fairly decently for itself, I believe. Plus, bat. Goodra is tanky and has good offensive flexibility, but lacks for recovery, which limits its usefulness as a wall outside of Assault Vest sets.
Including megas, you have Altaria, Salamence, the Latis, Sceptile, and Ampharos, not to mention Mega-Ray which, since I was just discussing Smogon tiers, inspired the creation of a new "tier" just for it. For a dragon face-off, Mega-Altaria seems amazing due to Pixilate (turns all Normal moves to Fairy, including Hyper Voice, which hits all opponents in a Double battle and ignores Substitute), its own Fairy typing, and the fact that it could either go Physical, Special, or mixed on the offense due to a decent stat spread and moveset. M-Sally is more dangerous in general due to its Aerilate (turns all Normal moves to Flying) and extremely dangerous stats, which apparently got it relegated to Ubers sometime after I stopped following Smogon. The Mega-Latis don't quite measure up to a Soul Dew-using monster attacker base form, but if you use Smogon tiers, neither are banned, and both have some use defensively. Mega-Sceptile is fun for doubles; Lightning Rod helps cover any electrical weaknesses, but that's less relevant for a Dragon team as Dragon already resists Electric. Mega-Amphy is best on a Trick Room team, where its low speed turns into an asset that lets it clean up shop with powerful blows, but otherwise is not quite so great. Mega-Ray almost deserves no mention; it's nasty, nasty tough, cancels out its own Flying weaknesses due to its ability, and it doesn't even need a Mega stone to evolve. I'm not sure it's quite Gen 1 Mewtwo levels of broken, but it's not for nothing that it was given its own tier.