Nikon mentioned Nikkor Z 600mm f/4 lens: typo or a leak?



A few days ago Nikon made a social media post mentioning a non-existing Nikkor Z 600mm f/4 lens:



The social media post was later changed to the AF-S NIKKOR 600mm f/4E FL ED VR lens.

Was that a typo or a leak?

Thanks br0xibear!