[prime17569]

That's the fault of the developer, not Apple. For example, Instagram hasn't ticked the box in Xcode to support the iPad screen sizes.

[oneeyedpigeon]

And, presumably, they're also only talking about native apps. You can still do whatever social media you want using Safari†.

†Apart from, I guess, any really bad social media things that only exist as apps. I think there's one or two.