Maybe not the worst thing.
Kids with the possibility of playing hockey post HS should be steered towards prep and U16/U18. It will give others a chance to play high school hockey in the MIAA who might not have gotten the opportunity previously. While it does mean the quality will suffer a bit I don't see it overall as a negative if more kids get to experience the high school game.
Have to agree with last poster, Rivers was very good this year. Really well coached and kids played really well together. Making it to the Elite 8 finals is nothing to sneeze at.