It's cool that the producers of this show are willing to share profits - it's their profit and should be dispensed at their discretion.
In terms of actors (and SMs, musicians, technicians, costumers, etc.) looking for a negotiated share of profits on future shows - the bar to clear is this: if you would like X% of profit, are you willing to either A) assume X% of liabilities if the show is a financial loser and/or B) work for a lower salary or nothing for the chance of a windfall later? The answer, of course, is no. So it'll likely be a non starter.