We really don't need to see those stuffs.
Oda touched them and that's all we will ever see.
And, everything is being set as a build up for God Valley.
Loki wasn't related to Reverie, to Roger's crew but we are still getting it as Xebec's quest is connected to Elbaph and Loki
My entire point is we focused on his interaction with Harald, aka Lokis dad...
It won't happen this arc
Wano: God valley introduced, Kaidos flashback shows before what happened
Egghead: start of God Valley is shown in Kumas flashback
Elbaf: set up for God Valley is introduced in Lokis flashback, since he looked up to Rocks(while his dad was "friends" with him)
Next arc: the flashback actually happens, from the perspective of someone who was present at GV