The whole point of the Better Together update is to allow all platforms play along with each other, so by segregating people based on their devices, CubeCraft would arguably be removing the primary attraction of the Bedrock Edition. Splitting up the playerbase would decrease the rate at which games may fill up, so although the games may be fairer, you might end up finding far fewer that will start.
It doesn’t make sense to me to send PC players to separate games when they have a whole separate network; if platform based matchmaking was implemented, why would a player choose to play against the few PC players on Bedrock instead of joining the Java server?