They never seem to be talked about in the context of Legend of Zelda games (in fact, seems like most handheld Zeldas get skipped), but they’re probably talked a lot about in the context of gameboy games.
For some perspective, the Oracle games are unpopular in terms of Zelda games. Zelda is one of the most widely popular video game franchises in history, though. So an unpopular Zelda game is still much more well known and well received than something more obscure.
The Oracles are some of the best selling and most well regarded GBC games in the system's library, though they are overshadowed by Link's Awakening DX and the glut of Pokémon games the Game Boy Color had on offer.