An official confirmation is still missing, but the press release from Mugen is unfortunately credible.
Archive - April 2018
Pictures from the Honda Monkey 2018
New Motorcycles, NEWS, Presentations
First road-legal motorcycle with winglets – Aprilia RSV4 RF Limited Edition
Before there are protests in the comments, I realize that the Kawasaki H2R also has winglets, but this is not eligible for road traffic.
Mugen will compete in the Zero TT in 2018 with Bruce Anstey, John McGuinness and Lee Johnston.
In addition to the Italian Stefano Bonetti, Michael Dunlop will compete on the Factory S1-R Lightweight Paton at the Isle of Man TT.