B6 576 is delayed 2.5hrs — Google says probably due to thunderstorms at JFK.

Flightaware seems to show the incoming plane is not delayed.

So is it necessary to arrive at MSY at the originally scheduled departure time?

Any potential alternatives for getting back to NYC earlier? B6 don’t seem to have nonstop routes to lga or ewr and I suspect the weather is the same there.

I see flight 2076 is also delayed. Is it possible to standby for it without status on a W class ticket if there’s only YEKH buckets available? Likely to work?

Alternatively, for the original flight If you don’t arrive at original departure time and the flight leaves earlier than 2.5hrs would JetBlue put you (flying on a W-class ticket with hand baggage only) on free standby for the next flight without making you pay extra?

Yes. If the plane is at the gate, they'll board passengers, and get the heck out of there as soon as ATC releases the ground delay at JFK. It might not take the whole 2.5 hours.

Besides walking over to another airline's counter and buying a new ticket? No.

Same day change/standby is $75. JetBlue's policy on same day changes/standby is dependent on open seats, not fare class. Since your flight is delayed, most counter agents will waive the fee, although they are not obligated to. If you pay the $75 standby fee, and you don't clear, it gets refunded.