i would rather it be only java, IF it also had bedrock features. bedrock has some really cool stuff like a friend system, easier multiplayer, and featured servers that i would love to see on java. the other thing i like about bedrock is the crossplay between platforms, so pocket edition, console and pc players can all play together.
mojang did say they want full parity between versions and eventually to merge them into one game, so this seems like the end goal anyway.
basically, i would want one game that's a mix of bedrock and java.