Quote Originally Posted by Rongway View Post
With respect, everyone who has said that you don't get SB and ShB access until EW official release (Tuesday 07 Dec) is wrong. In the past, people who preordered an expansion have always been granted previous expansion access as soon as the new expansion's early access period began. If someone has Starter Edition now, and they preorder Endwalker, they will get access to Stormblood and Shadowbringers at Endwalker early access, Friday 03 Dec.

Here is a snippet from the Stormblood Early Access Details announcement:
That does not seem to be true. See this official Endwalker Support FAQ

I pre-ordered FFXIV: Endwalker. How do I access the content for the previous expansions?
Although the Endwalker expansion contains previously released expansions, you will only be able to access the content of these first three expansions on December 7, 2021, when FFXIV: Endwalker officially launches.