It is not possible to cancel printing immediately after the start, until the heating occurs!

Printer should be responsible for getting itself ready to print, not the slicer.
With PRINT_START macro one can still use the gcode after updating the printer, for example switching from inductive probe to eddy or making better warmup sequence, it makes using the printer in a multi-user environment much easier as users don’t need to update all their profiles when the printer is tweaked.