I like this idea. Although I think there are times throughout the week when someone might want to post a question on a Thursday but can't because it's not the correct day of the week. And make them megathreads so they can be referenced throughout the week.
I think themed days for techniques, methods and practices of cooking would be fun. How about something like Ferment Friday or meal prep Sunday (I know it's stealing from Reddit but eff Reddit, Spez or whatever the case may be)
They sound amazing. I'm going to have to give them a try