Right, these are the kinds of characters he's talking about. 取, 撮, 捕, and 盗 are all different characters. Their 音読み are シュ, サツ, ホ, and トウ respectively. 聞く, 聴く, 利く, and 訊く are all き・く, but they're all different characters. Their 音読み are ブン(モン), チョウ, リ, and ジン(シン) respectively.
On the other hand, 駅 is a simplification of 驛, just like 択 is a simplification of 擇, and 沢 is a simplification of 澤. That was the first thing you brought up, and that's not what he was asking about. Those are simply 異体字.