I can't speak for the source of this info, but it's the first details we've had on an actual Porsche Taycan Release date!
The info comes third hand from a Porsche dealer or corporate employee... it's not clear.
It looks like it will be roughly a one year wait until the first deliveries take place. January 2020 is when it's expected to make it into dealerships.
The car will debut in production form in September of this year, which makes sense. I expect they'll debut it at the Frankfurt Motor Show.
In late summer those who put down deposits will be asked to properly configure their specific model. Presumably some versions will already be mostly built by then. Porsche was expecting to sell 20,000 Taycans a year, but they were surprised by interest and plan to double that number.
Maybe the most surprising news is that Porsche has actually closed the order books - although I find that hard to believe. Reading on Twitter I found one person who put down a deposit and they said their Seattle dealership already had 150 deposits!
Deposits range from $2,500 to $5,000 depending on the dealer.
If you haven't put down your deposit yet, do it!
UPDATE: April 18, 2019
We now know officially that the Porsche Taycan will debut in September at the Frankfurt Motor Show in Germany. Most likely on September 10th, the first of the media preview days.
Cars will be delivered in January of 2020.
To date, Porsche has said it has received deposits for the 20,000 models planned to be built in the first year of production. They have also doubled future production to 40,000 units.
As for the Porsche Taycan Cross Turismo release date, Porsche CEO Oliver Blume has said it will arrive "at the end of 2020."