I think the Dalelands are much more interesting than Myth Dranor, especially in this era of Cozy RPGs.
I think WotC should publish an entire Book of Cozy Adventures for the laidback rural idyllic. I'd focus the book on the Dales themselves, detailing village life, the Inn, a major festival and local 'situations' ( adventure seeds) like bad weather and crop failures, uncertain contracts, unresolved grudges, fey mischief and keeping the roads open and harvest steady.
Myth Dranor should come in the lingering rustic horror of dark roads and misty woods, unbidden dreams and relics washed down in a storm. The Zhentarim threat comes as warnings to avoid black wagons, foreign silver and unfair debts.
Book I: The Way of the Dales
Welcome to the Dales - Life in the Village, The Inn, Traditions and Festivals, A local 'Situation'
The Land and its Ways - Geography of the Dales, Roads, Rivers, Forests, Travel risks
The Dale Year Calendar - Seasonal Calendar, Weather tables and risks, Seasonal Tasks, Crafting,
Hearth and Hall- Inns, farmsteads, festivals, Guest-Right and keeping the peace.
The Dales Council -Politics and Intrigue in the Dalelands, Significant NPCs, Foreign Affairs
I think making a cosy collection is too narrow a market for an anthology, just as is a setting specific one. You can take a standard adventure and cosy or gritty it up to taste.
Whatever, I'm pretty sure the people at B&G wouldn't get excited enough over a cosy collection to want to make a big expensive boxed set out of it. If you look at what they have done before, you can see the sort of thing they like/consider commercial.