Why message "proofreadpage-disambiguationspage" is translated "Aimai" in Japanese?

I think this message is translated "曖昧回避" in Japanese. Why it is translated "Aimai" in Japanese?

You are talking about Proofreadpage-disambiguationspage (“Template:disambig”).

Reasons:

• "曖昧さ回避" is more natural than "曖昧回避".
• On jawp, "曖昧さ回避" is more frequently used than "曖昧回避". See Disambiguationpages (“Disambiguation pages”) and other messages.
• w:ja:Template:曖昧回避 doesn't exist.
• w:ja:Template:Aimai exists, and it is not a redirect.