Real advantages may be gained in new designs where the geometric constraint of a TRDS doesn't apply. However see my previous response on all electric, that step may never come.
Those already exist in the form of NOTAR, Twin rotor (Chinook) and contra-rotating MRs so it's not exactly ground breaking.
If it's not a good idea for the MR, why is it such a great one for thew TR?
Everyone would like to see a helicopter replacement that looks like a scaled up drone or quadcopter but to give it a useful payload is a long way from fruition.