I've done some pretty extensive testing and I'm starting to lean more towards towards the "Codies ****ed this up" category. I took a spin around Singapore using my 2010 "safe setup" with 3/3 height. I attacked the track at every opportunity, trying to simulate how I would drive in a heated battle (i.e. taking more curb then I usually do). I had no issues.
I expected this, since 3/3 in 2010 allowed me to attack the curbs (especially the Singapore Sling) without trouble. I then turned the suspension down to 1/1 height, expecting to have massive bouncing and other issues with the sling and other corners. I had none. None whatsoever. I then tried taking the last chicane at Spa by cutting the curbs at full power. Despite a bit of a bump, there where no other adverse effects. No launching in the air, no sudden control loss, nothing. It seems your original thought was right, there seems to be no downside whatsoever to running 1/1 right now.