They probably just want to balance it so that roughly half the bozja instance wants to do it rather than max participation 48/48 every time it pops. Right now castrum is the only way to get some of the best items and essences in bozja, and they may have initially thought that would have incentivized people enough to run it again to re-supply, which is why they didn't want to make changes right away. But it's clear now that that's not enough of an incentive, and so we can expect changes to happen eventually.