Bend Alot,
Let me add some context of why what you suggest is often impossible:
* Delays are fine and will happen just don't report it until you have information and plans to tell the SLF so they can make plans accordingly.
In this case they jumped the gun by an hour in delaying the flight.
They would have been better saying the inbound flight #xxx has been delayed (has departed/ is expected to depart).
If your flight can not depart by xx:xx time it will need to be cancelled/delayed due to crew duty hour limits set by law.
If the delay is at the airport then the cause of the delay should be known by the captain and in his absence the rest of crew in seniority.
The SMS could be sent to pax
Delayed due to
sick crew
late catering
weather
need more fuel
ground service equipment failure
paperwork discrepancies
or what ever is most relevant and give a realistic delay time.
Unfortunately, there are many times where we know the flight will be delayed, but we don't know by how long.
Take a maintenance issue discovered as the crew gets onto the airplane. Is this a 5-minute delay or a flight cancellation? We won't necessarily know until maintenance can diagnose the issue, go through their repair strategy in a logical manner, identify the need for spares, search for spares, obtain spares, install spares, test systems, and then complete the paperwork. Maybe the spare parts are not available and the system cannot be deferred. Or maybe there are spares, but what normally takes 10-minutes to drive, do the proper sign-out paperwork, and drive back will take 50-minutes today because the airport is doing construction on the vehicle access road, they are down to a single runway due to winds, and the maintenance guys have to cross the runway to get to the shop - otherwise it'll be closer to 120 minutes to drive the long way around (I'd like to say I am kidding about this, but a similar situation happened to me last year).
As an example, I once had an identical radio issue with two airplanes in about two days. In the first instance, the repair was completed in 10-minutes and we departed five minutes ahead of schedule. In the second instance, we had to swap to another airplane after maintenance attempted the most common fixes, including the one that had worked for me previously. We really did not know how long the delay would be, with every subsequent fix attempt just as likely to work as the one before or after, so we swapped once an airplane that would be sitting for a couple hours came in. But that airplane needed to be fueled (out of sequence), a new flight plan filed, all the applicable system checks completed, and up to 15 minutes given for the fluorescent floor lighting on the new airplane to energize because the lighting had been off for just too long. All of this might result in a 20-minute delay on a good day or a 3-hour delay on a bad day. Add in an ATC slot time, and you might find the flight now needs to be cancelled due to crew restrictions. A lot of this information builds on one another, so we often cannot give an accurate time for passengers to make their plans.
So, what starts as an engineering problem morphs into a fuel issue, which morphs into an ATC issue, and culminates in a crewing issue. If the airline were to let passengers know the actual reason for a delay, outside of "operational issues," that airline would look incompetent to the untrained eye. While you frequent a forum where line pilots share their experiences, the vast majority of passengers do not. They really do see flying as jumping on a bus. I've had passengers ask me on landing after a diversion why we couldn't have just refuelled the airplane in the air because they "saw it on the Discovery Channel." They're not stupid or incompetent, they're just out of their element, and too much information (detailed delayed codes) will often make the situation worse. They don't know a 737 cannot refuel in flight, but they know they saw an airplane do it on Channel 804.
Alright, as for telling you what time the crew will duty out...it's not for you to know. Sorry that comes off a little short, but it's true. If you're dealing in the short-haul or medium-haul environment, not all the crew may duty out at the same time. Also, crew scheduling might be working on a plan that will negate any crewing issues, especially where a base is concerned. Also, the last thing I need when I am dealing with an issue that is delaying a flight is a passenger yelling in the terminal or in the airplane for me to hurry up and "do my job." That's an added level of stress I just don't need as a Captain. It's also a level of stress the average passenger does not need, as they'll just end up looking at their watch and begin to harass the gate agents as the time creeps nearer to that deadline.
As for the crew knowing of a delay...yep, I wish that happened. But as people above me have said, poop flows downhill, and the pilots are often the last to know because there is no sense in telling them anything until there are solid facts. As you can see from above, there are often no solid facts for quite some time, so the crew often finds out just before the passengers. Heck, in my airline the operations department will tell the gate agents of issues through text at the same time they tell the dispatcher. As the dispatcher tells me, the passengers often find out a couple of minutes before I do! So it really does depend on where the delay is coming from, and who finds out first.