Am sure if it was selling out (which some were told on the phone) and there is now availability ... then they might have added more slots to the maximum they feel they can feed. Not sure when they came up with this, if they thought through that most will ride until the rope droppers arrive, then want eat breakfast OR maybe they did and maxing out the restaurant. If Disney is forcing some to eat during exclusive ride time I think they'll find less folks booking it.
I will venture if this is selling or close to selling out ... we may see it added to other mornings. I could for sure see it doing well until school starts back.
But to the OP's question .............. Disney does not release numbers. If a CM tells you a number, take with a grain of salt.
I've seen estimates that 7DMT can accommodate 1400/hr. Given that, any more that 700 people is going to spell longer than wanted waits.
The plus of the event if I were to book would be multiple rides on the mine train.
Fuzzy math.
If we divide the 1400 by 3 rides = 466
Let's say they up that to 500 assuming some will only ride 2 times.
500 x average (adult/kid prices) price ($64) = $32,000.
Most FL CMs are already there in the morning so we are talking about operations on 3 rides, kitchen/restaurant staff, food costs and some extra CM costs outside.
It may also be they will have some of the shops open so they could take in more income but probably not a lot.
Even if all these costs came to $12,000 (totally making it up and feel it's high) for that 75 minutes - they are still making $20,000 per morning.
$20,000 x 2 per week = $40,000 x 52 weeks (could be more if busy times are increased) =
over
TWO MILLION dollars with minimal effort.
Now lets add the evening After Hours .................
Up Sells are a great way to generate income AND keep offsite guests paying the Mouse instead of looking elsewhere to spend their money. The key is for them to know when to cap the capacity so that guests are happy, rebooking or giving good reviews for others to book.