>>31134082>majority>87 Gen 1 Pokemon>18 of those are new forms with new types, designs, abilities, and move poolsYeah, it's more than the Gen VII Pokemon, counting the Alola Formes, anyway. But it's not the majority. Not even a third. But not off by too much and it is more than any other Gen gets, though. By about double on average for any gen other than VII. There's no need to exaggerate when what's true sounds bad enough.
Anyway, this still allows all the Gen V, of which there are an appreciable number with the Island Scan, and Gen VI Pokemon in the game to be caught in Apricorn Balls, as well as the Gen VII Pokemon of course. Not to mention there are quite a few Pokemon from Gen III that couldn't be gotten before either. A very small amount, just 5 lines, from Gen IV are new too.
For specific Pokemon, the Gen II and V starters are there in the island scan, allowing the Gen V ones to be in something besides the basic one (And the Cherish Ball) at all. There's a few rather notable Pokemon from Gen I that are newly available too, despite HGSS. People probably care about Eevee the most, but this is surprisingly Scyther, Scizor, and Pinsir's first times they could be in them, due to being Bug Catching Contest exclusive, and thus Sport Ball exclusive, in HGSS.