I have noticed this problem today (07-02-19). Previously, flash was unavailable only in battery saver, but now there is no option for flash even when battery saver mode is off. Flash is working fine in video mode and in general. I'm not entirely sure if this due to the January patch, it's just a hunch. Any ideas?
I'm attaching a screenshot of the camera app, notice the absence of the option for flash on the top right.