This is still not true. There was one beastmaster in Celestial - Benika xp2. Zero in Emperor, and one in Ivory. Half of all beastmasters appeared in Twenty Festivals.
Fair enough, although I will point out that there were at least two beastmasters (including basic Benika) in Lotus. I didn't pay much attention to which got printed where.
Dragons have always had tattooed monks and dual wielding samurai.
If by "always" you mean "Starting in Jade Edition" and "starting in Shadowlands" respectively. So, not quite always.
(the first personality with both Tattooed and Monk was the Jade Edition reprint/errata of Togashi Mitsu ; prior versions were tattooed but not monk. This was quickly followed up on thanks to the Dragon civil war and the Hoshi hiding in the brotherhood plotline going on at the time. The first dual-wielder was Mirumoto Taki, and the NEXT one after that had a Gold Edition bug on him (Mirumoto Tokeru in HoR). After Taki (and his soul of), the next Non-unique dual wielder had to actually wait until Dark Allies.
Which is pretty much my point. Themes were not "always" there. A lot of themes took an eternity to develop properly, and most themes were later extrapolations from a single card. Beastmasters are no different in that regard.
That does make me wonder if new themes will be devised for the clans.
For the initial launch, I don't see a reason to. Maybe several years down the road.