As long as any threat of litigation is dropped (which the recent article quoting Leigh Clifford seemed to suggest) why wouldn't RA back the consortium? If they really do have $20-30 million of backing, then it at least guarantees the Rebels viability for a few years so why not give it a shot? Melbourne/VIC is too big a market to give up on with this kind of investment on the table. It also gives RA more options in case Super Rugby falls over post 2030 (easier to start a domestic competition with 5 pre-existing local teams than 4!).
But personally I've become more optimistic about the potential of SRP (Super Rugby Pacific) this year. It'll take time to turn things around, but the quality of the tournament this year has been pretty good, and I think there's a few easy wins out there for RA and NZR to grow the pie for everyones benefit.