I don’t play Runescape so take all of this with a grain of salt, but… It looks like on character creation you would have been able to create a new “reignited” character, who cannot trade with “veteran” (non-reignited) characters. They would also have access to their own reignited-exclusive worlds (though they could join regular worlds with veteran players). Essentially, it sounds like the goal was to reset the economy for new players so they could experience it as if the game came out today with 25 years worth of updates.

Idk what they were thinking, splitting your community in two by making it so your current playerbase can no longer trade with most future new players sounds like a fucking terrible idea.