Here's my theory: this slim version is indeed real and is what is being teased to be announced in September (meaning it's yet another Sony announcement leaked ahead of time).
It will be released later this year to counter the Xbox One S, while the Neo will only be mentioned at the event (and perhaps shown indirectly with a Microsoft style "devs comment" video) for a release next year with updated specs from the leak/rumor (to be more on par with Scorpio) and to give devs more time to adjust.
This is all pure, baseless speculation and I could be 100% wrong, but that's what my gut is telling me.