in my opinion - the pirates don t have the knowledge to make jumpdrives - not to mention not the resources to operate them - if we think of the engines still consuming fuel. - which they usually don t have in their home systems.
so - either the pirates would finally make a desperate alliance and attack the core in one desperate attempt to destroy not only the weapon, but also the plans and people who know about it - or they ll be forced to comply to what the core wants them to do.
such a weapon is much like a nuclear bomb. - it looms over the heads of those that don t have it - ever present and inevitable. - their power would fail and they d become puppets of those that have access to the weapon.
if they do not comply, and the weapon is indeed used to cut them off - they would die. - isolated in the rim worlds, there is not enough resources to really survive - well, almost.
the zoners can provide food. the nebulas provide ice/water. - there are gasclouds in the omicrons that might be extracted for fuel - or the pirates find other ways to operate their ships. - technology would stagnate, but revive after some time.
what the core would do in the end is to isolate itself - and one day in the distant future, they could be overwhelmed by the borderworlds - cause the borderworlds can endlessly expand, the coreworlds are trapped inside - unless they find ways to MAKE wormholes to distant places.
but the most probable scenario is that the corsairs and the outcasts destroy each other even more. - not even the nomads made them work together. - oh, and the core pirates that are on cardamine would prolly die, cause there s no resupply anymore.