Implementing a panel in Plasma 5.8 needs a layout to accompany it?

[Marco Martin]

On Tuesday 27 September 2016, Michail Vourlakos wrote:
> Hello everyone,
> 
> 
> I am receiving reports that Now Dock Panel in Plasma 5.8 even though is
> installed correctly at the same time is not appearing in the panels list.
> 
> Do you know if there is a change is the plasma codepage and the "Empty
> Now Dock Panel" must be provided also as a layout?

that may have sneaked in the beta, yes.
5.8 final release tough should allow that again
tough pay attention the metadata desktop doesn't have NoDisplay=True
that means the thing would appear in the widget explorer as well.
if you really need for it to not appear in widget explorer, so have 
nodisaplay, then yes, you need a javascript layout template

-- 
Marco Martin