Tesla has done this for a long while. Newer larger battery pack options, newer interior and tech package options, and completely new performance and configuration options (insane, dual motor, and autopilot 1.0 all hit at once)
While there wern't announcements ahead of time what was coming, there were often advance notice that there was an announcement coming, and even when there wasn't - there was a big period of quiet from Tesla leading up to it.
For Autopilot 2.0 everyone knew it was coming for at least the Model 3 launch (Elon said as much at the Model 3 announcement), they just brought it forward.
It is really no different to what happens to customers for a bunch of other tech companies. Canon sure doesn't tell anyone when their new models are coming out - you know it'll probably happen at a major trade show, but only if you're someone that follows that kind of thing. The average customer at their camera shop isn't going to have the sales guy say "Hey, wait a week and we'll have the next version available."