COMPUND STRINGS for SERIAL.PRINT()

You can already use multiple serial.print() statements to achieve the output that you want, or use sprintf() to create a string to output.

You can create your own function that takes a variable number of arguments and outputs them individually.

There is also a Streaming library.

Given that there are already at least four ways to accomplish your task, I see little benefit in encumbering the Print class with more rarely used capabilities.