I was doing some searching on saddle bags today and came across a website selling the official pannier bags with a release date of March 16th. They list the date as coming from the dealer. There is no reason to release the bags before the bike and if they are starting to arrive at dealers the date must be close.
Ducati Scrambler Urban Enduro Waterproof Pannier Set 96780421A
Ducati Scrambler Urban Enduro Waterproof Pannier Set 96780421A