>>30550129I decided to compile a list based on gen to check your claim:
>Gen 1:Lorelei, Bruno, and Agatha never appear outside of their respective rooms before you encounter them
>Gen 2:None of the Elite 4 appear outside of the Indigo Plateau before you first encounter them in that gen specifically.
If you include Gen 1, then Bruno and Koga were both encountered.
>Gen 3:Sidney, Phoebe, Glacia, and Drake are all encountered for the first time in Ever Grande City, though Phoebe and Drake in Gen 6 can be re-encountered in Mt. Pyre and the SS Tidal respectively.
>Gen 4:Aaron, Bertha, Flint, and Lucian are never encountered before you first see them in the E4.
Flint, however, does reappear post-game in Platinum.
>Gen 5:Shauntal, and Grimsley are never encountered before you first encounter them in the E4.
Shauntal, however, can be visited post-game in Cynthia's villa.
Marshall is referenced at Twist Mountain in Pokemon BW, and appears in front of Twist Mountain in BW2 if you attempted to go there early.
Grimsley reappears in Pokemon SM.
Caitlin appeared as early as Gen 4, where she oversees Castle Valet Darach, and reappears at Cynthia's Villa.
>Gen 6:Wiksfrom and Drasna are never encountered or referenced before you first encounter them at the E4.
Malva is first seen on the Holo-Caster, long before you encounter the E4.
Siebold is mentioned offhandedly in Restaurant Le Yeah.
All four cna be re-encountered at the Chateau.
Gen 7 is the outlier, where you know and interact with three out of 4 of the E4 long before you face them there (and of those, you battle two of them beforehand!), four if you include the "Champion" Kukui. And even then, Kahili IS mentioned in the Hano Grand Resort.
