转注 is closer to "mutually defined" i.e. mutually recursive definitions (or potentially sounds, it's not really clear as I explain later). There is no reason to think this referred to any notion of derivative cognates.
Indeed if it were derivative cognates there would be way way more characters in that category than are put there (e.g. 手 and 又).
Basically nobody really knows what the intended purpose or meaning of 转注 was. This is because, although the Wikipedia article mentions 考 and 老, it fails to mention that this pair is the only commonly agreed upon instance of 转注 in the entire Shuowen Jiezi.
Xu Shen (the author of the Shuowen Jiezi) writes, "转注 consists of those characters forming a single category with the same radical. The same meaning is mutually given among them. 考 and 老 are examples." (转注者建类一首同意相受考老是也）。Indeed if you go to the entries of 考 and 老 they simply refer you to the other.
That is the entirety of what we know about 转注 (barring later interpretations by other scholars trying to make sense of that). No other character is listed as 转注 in the Shuowen Jiezi's 10516 catalogued characters (to be clear not every character is necessarily categorized by Xu Shen among them, many are categorized by later commentaries).
As a result scholars mostly ignore 转注.