How dangerous is a very out-of-true disc brake wheel?
Another danger of riding an out-of-true wheel is cornering.  When on the straight, the wheel may be "round" while wobbling from side to side.  

But when leaning into a corner, the bike is no longer vertical, so that out-of-true in the rim is translating to an out-of-round as well.  So the wheel of the bike will be rising and falling ( "oscillating" ?) sideways at roughly twice the wheel's RPM.

Effectively that could make the wheel loose traction much easier on the faster corners, or even at moderate speeds if the corner has any treacherous features like dampness, dust, sand, gravel, or even painted lines.