Good suggestion, it is a baffling ommission. What’s weird is that the departure time is included in the short-form alerts (sent to mobile email address in your profile) already. I honestly have no idea how we missed putting it in the long form alert (sent to full email address in your profile).
I’ll make sure this is added in the next alerts software update.
Actually, we don’t. FlightAware just has email alerts with the option to deliver a shortened alert to your mobile device if it has an email address.
These aren’t “real” SMS/text message alerts. It’s possible that we’ll add text message alerts in the future as a service available to premium/paid account holders, but there’s no free way for us to send SMS messages. It’s not something we could provide without cost.