Yes, the toggle reappeared in that build, in build 18353 it doesn't appear, the title of my image is wrong. In Skip Ahead the toggle disappeared in build 18841.
I'm more optimistic, let's see what wzor says about 18361, if it is speculated RTM I'm pulling the trigger.
RTM is when you get the 3 features : 1) Header 2) Automatic hamburger menu. 3) Friendly Dates (I don't have it).
Exactly when Microsoft officially confirmed that those 3 features would arrive in version 1903? I'm not saying that they will not come with that version, but in the past, there were several features that were tested in the insider builds and never reached the stable version or they came with another feature update.
I don't know when they confirm, but when the first 19h1_release released (18323) I got part of the new features : automatic hamburger, … menu of win+v, expanded emoji and more.
But you sure know that such features are there for testing, they can get delayed or even binned completely. This process is controlled by Telemetry and User Feedback. So, not everything appearing in an Insider Preview is a keeper...