343s edition of H3 is legit, and the market demand for H3 is high. Players want this.
If you’re referring to MCC, there’s an entire section for MCC you can use. And there’s a ranked Halo 3 list.
If you’re referring to Halo 3, there’s the Classic Halo games section to use. And there are ranked lists in that.
If you are referring to a hypothetical H3A, that’s not happening and this is moot. 