Thank you M60_to_LGA. They do fly near-daily. I'm glad you agree it's a problem also, I do not live in Mexico so unfortunately I am ignorant of how things normally work there.
Volaris was not my first choice for a flight. When I booked there were extremely limited options, even though I booked as early as possible. Now I know they are not an option, even if they are the only option.
Their changed dates had me leaving at 1:00am(!) in the morning two days earlier(!) and a too-tight connection in MEX, altogether doubling the flight time and pretty much guaranteeing failure at some point in the trip.
The cynical side of me believes corporate is trying to lose people around who bought tickets before Volaris realized the solar event was happening & increased prices, so they're trying to force cancellations.
It hurt, but I booked another flight (10x the cost, ouch) as I no longer trust them to get me there on time (or trust them at all, really). My wallet is still smarting and I'm hunkering down for a long fight with Volaris for a refund.