This is a solid piece of info. Dolly Parton would, obviously, be in a position to know what Sanddollar or it's partners are doing, as opposed to which ever actor is being interviewed this week. (Yes, I'm sure Felecia Day is in constant contact with the producers, and David would just love to stop whatever he is doing to play Old Man Angel)
Having said that, eh? It's not useful. Consider, Kuzui Enterprises tried to produce a remake of Buffy as early as 2009. Do you think that they ever really stopped trying to do so? If Untitled Buffy of Color Successor Series is "still" in production, that's 2018, that's 6 years, just since the announcement. They are producers, they are always trying to make money from their production. They are like the supporting cast from one of those Nickelodeon shows with a minor cast, they are always game for a reunion.
What I would take seriously is a casting announcement, or a Broadcast or Studio partnership, or a financing deal, or a showrunner (Executive Producer who is also head-writer) being contracted, or a production order of some kind. Something that indicates that someone is willing to spend money on this project, and is doing so. Contracts are real, gossip is not.