I picked up Automobile Magazine for a recent plane flight. The one with the proposed 718 on the cover.
In the review, the Magazine suggested that the original plan was to insert the 718 as a $40K four cylinder. The Cayman would be above and the Boxster between the Cayman and the 911.
Then they said that the changes in plans by the likes of Alfa Romeo and Mazda are causing a rethink. They suggest it is possible that the 718 will come in as slated. The Cayman will stay where it is and the Boxster will be no more.
That strikes me as really stupid. You have an established brand and a model lineup (leave aside that it makes no sense for the coupe to be more than the convertible). Why abandon it for an alphanumeric code?
Like anything else, this might be just drivel to sell magazines, but ...