Thanks! I didn't know I could turn that off. I "solved" it by wrapping chrome with my own home grown tooling to maintain multiple parallel profile directories, so I could run "work chrome" and "chrome for gmail" and "chrome for web browsing". Of course, now I use firefox for all 3 so I don't have the problem anymore... :)
Its a paranoid reading of the normal launch process.
Behind the scenes every major change like that is a flag that's deployed first off then slowly flipped to default true as a rollout so that it's as low risk as possible of unintended damage / failure.