I've seen that before. There are so many variables there. It could be Ford's server being slow, it could be the text system, etc.
I have both MyFordMobile and ChargePoint setup to send me texts/alerts. At times I've received alerts/texts from both immediately and at times they have been hours later.
With Chargepoint my phone has beeped while the charge plug was still in my hand (saying: "Someone unplugged you"). With MyFordMobile I usually get the alerts/texts on time but sometimes its much later (when I wake up I usually see the two alerts: "Beginning to charge" and "Charge complete" but sometimes I'll be backing out of the driveway and my phone will beep...).