If there's a PS4 double-slim, it would probably get announced at E3 in the PS4 portion of the presentation, either as the first thing they talk about or the last thing before moving onto the PS5 section. I'd assume that it would be the first thing, with Jim Ryan talking about Gamescom 2013 and being there talking about the start of this generation, where they are now, and how there's still a fair amount of stuff coming for "the second-most popular home console in history", which people will be able to get easier than ever as he announces a price drop to $229/$199 and they show this revised shell for it that's either like a "flattened" current slim or looks like an "alternate" shell for the PS5, assuming they show the PS5's shell at the official announcement months before. Those sorts of pressers are like the only time those sorts of announcements usually make sense - it's always either going to be that, or just putting up a blog post and sending out a press release.
I say they'd probably start with it because if they close the PS4 section with Tsushima they're going to announce a Pro bundle for it.
The PS Meetings are, without fail, about one sole product whenever they hold them. They did a PS Meeting for the Vita, for the PS4, and for the Pro (I sorta guess they did a tiny GDC one for the PSVR, too... I guess). At no point do they go "oh and we have something for the [previous gen/handheld product] too!", it's to hammer in what the new product is and what it does and how games look on it and yadda yadda yadda.
Honestly, I always find trying to guess the logistics of the announcing of this shit fun. Who will show up as a "regarded partner" (besides whoever's at the head of Gearbox Publishing or whoever's running Counterplay, as I imagine Godfall will be in the Meeting)? How will they try to create a sales pitch out of what they've already talked about? How do you show off the haptic feedback stuff for the controller? How many minutes do they give Mark Cerny to talk to us about the new system? Which first parties actually have a thing to show in time for the meeting? What indies do they lock up for a period of exclusivity? Do they do something crazy like have cross-buy with the Epic Games Store for applicable games to match Microsoft's cross-buy across Windows and Xbox? Do they talk about PlayStation Now? What does Ubisoft bring - "we ported the PC build on Ultra settings to the platform on this almost-out title" or something new? Will some more computationally simplistic indie be shown rendering internally at 8K?
