Who is "safer" in the AI era: IC or management?

Management. All automation creates more vacuum for bureaucratic nonsense to take over. IC will be worked to the bone, maximizing utilization on whatever precise task still can't be fully automated (grasping arbitrarily shaped and positioned objects) and more management will be added to culture teams or whatever useless functions companies can spend the freed up money on to signal their prowess.

Can you find any time in recent history where legions of managers where on the streets, unemployed, and IC's were thriving?

The integrated circuit is definitely safe in the AI era. Not sure about management.

Neither? AI is capable of doing both roles.