The adjectives vipariṇāmin and aññathābhāvin rarely in the Early Buddhist texts. (Try the search terms “aññathābhāvin*” and " vipariṇāmin*".) According to the Pāḷi grammars at my disposal, the forms vipariṇāmino and aññathābhāvino can occur modifying nominative plural nouns only in the masculine. However the given adjective forms occur modifying nominative, neuter, plural nouns rūpā and phoṭṭhabbā.
Neuter adjectives in -in are very rare. The suffix is mostly used to refer to persons, that’s largely why.
Other nom. plurals neuter (along with other cases and numbers) do also rather frequently adopt the masculine endings. E.g. -ā instead of -āni for the a-stem neuters. Also, many other neuter endings are identical to the masculine. In other words, it seems like the neuter slowly got “lost”.
So it’s not surprising to me this also happened here.
Thank you so much! Yes. The examples found in the search I give above are cases where a neuter noun has a masculine ending in the nominative plural. I didn’t notice at first because I don’t have the endings memorized yet. I think there’s a subtle grammatical point that I’m missing here. I’ll continue to investigate.
Add “wisdom” and we might say, “A wise one who is righteous” or something like that.
Often, though, there’s no suffix to explicitly indicate this, as in my name sujāta “one who is well-born”. And the same thing would happen if your name is shortened (or when paññā occurs as the final element in a name).
In all these cases the name is declined like an adjective. i.e. it has no intrinsic gender, but is implicitly assigned a gender agreeing with the subject.