I'm not sure I agree with that. The SoCal and NorCal markets are distinctly different. Mammoth/Big Bear completely owns the SoCal market, both before and after the Aspen/KSL deal.
NorCal skiers know about Mammoth, but almost none of them actually go there during the winter because it's a 3-hour drive beyond Tahoe. Even on the July 1-4 holiday with Tioga Pass open, Squaw was overrun despite the far superior skiing available at Mammoth. People with a base in South Shore will probably stick with Epic as Heavenly is right there and Kirkwood not that far. NorCal skiers/riders have zero interest in Big Bear and barely know about June.
Where does someone live/have a ski house that adding Mammoth to a Squaw pass moves the needle vs. Epic? Minden/Gardnerville are an extra hour closer to Mammoth but Heavenly and Kirkwood are the most convenient areas for them.
I think quite few Tahoe skiers get Epic Local plus Mountain Collective, and will be happy with that arrangement unless/until Aspen/KSL decide to change that situation.
Tony I realize you are very analytical and a long time statistician which I appreciate very much. But it comes down to one word, Terrain. Squaw Valley and Mammoth Mountain have the best ski terrain in the state, hands down, hence my prediction that it will cut into Epic Pass Sales.
Also with the assistance of the new ownership group, look for Mammoth airport to finally divert flights to Bishop when weather is an issue. This will lead to more Bay Area visitors to fly SFO-MMH, once air service is deemed reliable.