From GameWatcher: “Frontier Developments has announced adjustments to Elite Dangerous: Odyssey’s release schedule which see the upcoming expansion arriving later on both PC and consoles. Out of the two, the PC launch remains closest to the initial Early 2021 window.
Elite Dangerous: Odyssey’s alpha access will begin in early spring, owners of the Lifetime Expansion Pass and the expansion’s Deluxe Alpha version getting access to this early version of the game.”
Source: N4G PC Elite Dangerous: Odyssey Targeting Late Spring Release on PC, Autumn Launch on Consoles