Not quite. Video was posted yesterday which is April 9th. No indication the video or the test drive has anything to do with April fools. If it's supposed to be an April fools joke, it's pretty dumb and a week late.
Text from the actual Youtube video:
Published on Apr 9, 2016
My good friend Adam (aka. Kevlar Condom) recently had Tesla upgrade his car from Model S P85D_ Ludicrous edition (762hp) to an option that is not publicly available referred to as 'Secret Sauce'. I can't give you the figures on it since they haven't been made public yet under NDA but I can say it's a HUGE step over Ludicrous edition especially on the big end. I can't imagine how this car could get any faster!
Though it is feasible that were it a prank, that the audience would be limited, one has to also consider that the audience just might "not" be limited too.
In other words, if it is a prank, well then yes, it may have been aimed solely at us. But if a prank, well then it may also have been meant to involve other auto enthusiasts, e.g. Hellcat owners, etc., in the collateral damage.
But you bring up another good point. If this was an April Fools prank, then why the video on April 9th?
It's tough to know what to make of this at this point.
There is also talk elsewhere of a body style and other refresh of the Model S. I recall the announcement of Ludicrous. It came with 2 other announcements and was referred to as "3 Dog Day" if I recall correctly.
Perhaps this announcement is meant to accompany the announcement of the changes planned for the Model S.
Finally, if this is a hoax, well then they dotted all of the i's and crossed all of the t's.
By that I mean even going to the trouble of using language indicating that whatever this is, requires the agreement to disclaimers.