>>30548659Generation IV had encounter info specifying a Pokémon came from Johto, but at that point, only Hoenn, Kanto, and Sinnoh were possible regions for Pokémon since GSC weren't compatible with future games. HGSS did receive more intentional foreshadowing than ORAS.
Ever since Generation V, pretty much every region has been referred to in the games, so saying "This part referred to Hoenn" doesn't really mean much when every other region got the same treatment. However, it wasn't really like that in other games. In FireRed and LeafGreen, Gideon says this the final time you deal with Team Rocket in the Sevii Islands
>What? You again? You... You're not Giovanni's kid, are you? No, that can't be right! Giovanni's kid has red hair! You don't have any reasons for bugging me. Leave me alone!It was probably the first real foreshadowing for HGSS, as Silver's identity as Giovanni's son was never even speculated before that. Pokémon Special took that and ran with it, outright confirming it in its FRLG arc (the arcs coming out after the games).
I think it was around this point that Johto became a teaser region for the next 5 or so years. Emerald let you get one of the Johto starters for completing the Hoenn Dex, XD had Shadow Lugia, Espeon, and Umbreon, all of which were unavailable through normal gameplay in the handheld games. Colosseum had Ho-Oh and the second stages of the Johto starters after beating Mt. Battle, as well as Celebi from the bonus disc in Japan. FRLG and Emerald had a bunch of Johto Pokémon added post-game, including some special ones like Sudowoodo, Smeargle, and the Unown. But it also changed the information at the beginning of the game that Brendan/May came from Johto, and changed it to the vague "another region". Ho-Oh and Lugia were Mythical Pokémon until HGSS, with a special event at Navel Rock.
DP had a ton of little teasers, from the gold/silver Poké Ball in the Pokémon Center, to the Red Gyarados news report, to Park Balls.
