Once that is established and the other oil companies start using the EC225 the economics will come into play and they will follow. Everybody knows the EC225 gives better payloads / range in most cases so the operating cost will be lower and this bottom line is what the beancounters are interested in.
I think that the 175 / 189 will fill the medium range market at a lower seat mile cost. The S-92 will continue to fill the longer range heavy requirement as it now does reliably. Contrary to what many think, the workforce does have a voice and won't welcome the 225 back if the stats are true. The return of the 225 is potentially therefore commercially irrelevant. Even if it came back at half price, which oil company aviation department is going to take the cost vs safety risk?