The rate at which your nitrates rise will slow thanks to less waste. So, if you keep up the PWC
's at your current level then your water conditions will improve (same water change, less nitrate rise). Or you could change your PWC
schedule based on the lower bioload to give yourself a bread. Of course this assumes that you are also adjusting the amount you're feeding based on what's left over there.
You bacteria colony will start to die back to balance themselves out with the new/lesser inhabitants and the world will be in balance again.
Either way the corals should be happy.
Good luck on the new tank