I still think that he will have his own flashback but what makes you think he will be part of someone's flashback here in Elbaf? I can't find any connection.
I just believe that We are gonna see Loki & Shanks Flashbacks this Arc,
I think Elbaph & WG share the same Flashback (Similar to how Fisher Tiger & Otohime shared theirs),
Remember how Loki was hated even before He was born, & it was only 6 years ago that He was Captured. So Elbaph Flashback gonna cover entire Story of how Elbaph changed since Carmel's Time, Garling's Generation of Holy Knights, Formation of Rocks Pirates, God Valley Incident, Harald's Story with Holy Knights, more of Roger Pirates, Shanks forming his Crew & his entire Adventure, Loki's Adventure ... etc
In other words, i expect "Everyone" to appear in this Flashback, Oda doesn't have the time to keep drawing Flashbacks as long as Kuma's for every Major Character, He simply needed to Introduce a Character who lived throughout all their Stories & got directly or indirectly involved with all of them.
It's clear to me that Elbaph & Mary Geoise are like Water 7 & Enies Lobby, They are One Arc,
Loki is our Franky, while Shanks is our Robin (Survivor of God Valley Incident which is gonna repeat itself just like Ohara Incident & Buster Call),
So this Arc = Flashback of Loki + Shanks (Spanning +70 Years of History Reveal)