This is def no treasures of tokuno system
You're absolutely right. We increased the chance of getting Invasion minors by half over Treasures of Tokuno minors. You also have two opportunities to get guaranteed minor artifacts by killing Captains (a guaranteed drop to a random "top attacker") and destroying the Lighthouse (a guaranteed drop to all "top attackers") whereas ToT had just one...also these guarantees are independent of the points you accumulate from killing Captains and their minions. To put it into perspective, in the first day on TC1 a single player was able to collect 24 artifacts. Also, while the Invasion will not last forever - the ability to get the Blackthorn artifacts will have a permanent place in future content.