I am pretty sure it would skyrocket. AGs like you would announce it everywhere and tried to draft as many new players as possible so that first month would see massive PCU improvement so that you could leverage it as “ganking ruins this game and needs to be removed completely”. CCP will then comply. Then the game will slowly fade away without destruction in highsec, and EVE will soon be dead game. It is pretty obvious and it happened already in EVE Echoes.
More than 50% players lives in highsec and will never wander into low and null unless perhaps travel with BR, shuttle or pod. And removal of ganking won’t change that. They will not go into low or null just because suddenly they can afford it (as they are not losing ships to gankers anymore). With no destruction everything will soon cost peanuts because there will be insane offer but very little demand. And since ISK is fun, if players are not making any ISKs from mining and mission running they will quit.
This is so easy to predict, only AGs don’t see it. So either they are just that stupid, or their goal is to destroy this game. Possibly both.