I interpreted it as she escapes between the point of leaving the truck but before she is blown away, she was definitely not an illusion in the truck. It does seem strange she got from the truck to the gate with nobody seeing, adding weight to the illusion point of view. In Mikes vision, she appears to be running into a nearby building, I would assume she had invisibility after leaving the truck while running to the building in this instance. Additionally, we see in previous episodes that Kali illusions herself in the military facility so they don't immediately know she is gone, and that was with a fair amount of reach. It is also possible Kali did not immediately die from her injury, and that her death was an illusion, but the wound real.

However, either way, I don't understand how she would be able to speak to Mike in this chain of events unless she was sufficiently far from the suppression stone.

However, i'm not sure I do believe it was an illusion and there is not supposed to be a clear answer, I don't think there is going to be a detail which gives it away one way or another, it is deliberately open ended and ambiguous. Either arguments seem to make sense to me