I feel like the problem with any specific spoiler rules beyond those normally in place is how exactly would people know about them? It would be unfair to punish people for a rule that they're unaware of.
That being said, if I see a thread title mentioning a specific game, I'll edit it out.
Another option is to make a stickied spoiler topic specifically for leaks relating to the Sony conference, so that people will have one topic, with a spoiler free title to post anything. I'll run that by the mods and see what they think.
To have a category for spoiler on thread creation which doesn't show on main page would already help some as well... the rules are available to everyone and can be edited. Also a day ban and locking thread isn't that harsh, at most after the event comes out you can just remove it from person mod history to not increase lenght of other bans.
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"
Azzanation: "PS5 wouldn't sold out at launch without scalpers."