@LadyBrasa
Adding new species is something we've often left to DreamWorks, we "met in the middle" somewhat with the breeding.The decision was partly due to this, but also because (as you mentioned) we did see clear signs in the fan community that pairing Dragons and breeding them was in high demand. I was a big fan of this system in Fallout Shelter, myself, and I thought it would be a fun mechanic to add while allowing us to create "new species" from already existing ones.
As for the game-lore aspect of this: crossbreeding is NOT limited to Berk. They are encountered in the wild, and Fishlegs even points it out when you first encounter one, shocked. We'll see what the Riders (especially Fishlegs, who is CRAZY curious like yourself about this) discover to answer this very big question. But I will make sure it's clear this is not Vikings designer-breeding Dragons. I don't think that's something Hiccup and the gang would ever do for their own benefit.
I know, there are conflicting opinions on crossbreeding on genetic levels, but after I saw a zonkey and a liger... yeah I accepted that nature was stranger than I gave it credit for.
For timeline: Titan Uprising falls after HTTYD2 but before Hidden World, in the same "universe" as Rise of Berk, so to speak (meaning we will always be as true to the franchise as we can, but are "parallel" to the "real world" of HTTYD.)
Ah! And a question I'm very excited to answer, as it provides some good context for big fans like us in the game:
Draft Tokens are used to obtain Dragons from Berk, without breeding, hatching, or rescuing them in the wild. The way Draft works is, you're a member of the Berk Dragon Academy, and a Draft token gets you a random Dragon from the communal pool of Academy trained Dragons. It ties into our leveling system:
When you Level Up your Dragons, you select up to ten to donate to the Berk Academy for other trainers to learn with or adopt as their own. The more Dragons you donate, the more your own Dragon Levels Up from the shared experience gained by Trainers learning with your Dragons.
I mean, sure, it's clearly a game mechanic haha, but I'm a HUGE HTTYD fan, and I really, really wanted to push the sense of community within Berk and with other trainers - so that's how I've decided to explain our leveling system and Drafting. I never wanted it to just be "oh you level up with other Dragons" - I always wanted to encompass a purpose behind this, especially one that I felt fit: helping other Trainers in the Academy.
In short: Draft Tokens are simply a token you receive to get a Dragon from this community pool of the Academy Dragons. We still have the usual Runes as our base currency (along with Gold/Fish for more minor costs).
I know on your main page for the game (thanks, btw, you guys are fast) it talks about "Releasing them", which was an early discussion for the level system which I'm looking to update with my above explanation once I find out where it's being revealed as such.