Where are you getting this from? Is this from the complaint? Or a personal anecdote?

I worked there in 2006. The SVP of Eng was Alan Eustace. He's a jolly guy, he chuckles a lot. I don't remember this specific exchange but I can hear his chuckle in my head. Knowing him, the chuckle would almost certainly be laughing at what an obviously terrible idea it would be to delete the emails. Alan Eustace certainly would not have instructed people, explicitly nor implicitly, to delete messages subject to legal hold.