SCAG and STK cover at least 1/3 - 1/2 of what they'd cover in an updated FRCG, we're not getting it.
I'm not buying any new material for 5E. This edition is dying, and I don't want to contribute toward unnatural attempts at prolonging it.
No, I don't think so. I have both the 1e and 2e FR boxes, along with the 3e FRCG. I don't think I'd want a 5e *update* of any of those. What I would like is a truly 5e FR campaign guide of some kind. One that is set in the late 1400s DR and covers more than just the Sword Coast. It does seem like we're getting that piece by piece (Out of the Abyss covers [part of] the Underdark, Storm King's Thunder covers the North, Tomb of Annihilation will cover Chult), but I'd like something along the lines of SCAG but with more detail, especially for other parts of Faerûn.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.