Parmandur
Book-Friend, he/him
I am not actively against the idea for myself: I love the 3E FRCS, still use it even (and notably WotC still sells it, and the 1E, 2E, and 4E versions).I'm not sure why you're so opposed to the idea, at least as far as it making sense - not whether or not you personally want it. I mean, Henadic puts it well:
I don't think you're right that one of the next three major releases with be an FR setting book, although it wouldn't totally surprise me. But I agree that they really should do one at some point.
I didn't see this one. So they're actively working on two others, but may have others in their long-term plans.
"Actively" would probably mean it is going to come out within the next year or two (by 2022, maybe 2023). So it may be that we don't see another this year, but see one in each of 2022 and 2023, and that they plan on covering one per year, at least until they get through most of the obvious ones (Ravenloft, Dragonlance, Dark Sun, Planescape, Forgotten Realms) and then re-assess for the "second tier" (Spelljammer, Greyhawk, Mystara).
However, I see no business case for anything beyond the SCAG while it is still selling and the Adventure supplements with Setting info still sell, so I don't see WotC doing anything different with the FR by 2024.
In the D&D Studio blog, Winninger also said that book projects take 12-24 months. So I think we might see both things he is talking about within the next 12 months, potentially.