huh so this is a new update to e-hentai then? since we scrape from there, will the e-hentai galleries with the [japanese | definion ...] tag be redirected to the [japanese] tag here on nhentai? or will they continue to create a new [japanese | definition ...] tag if this merge goes through

Not by mistake, it's just a case of the scrapping to E-Hentai. It's a tag for the japanese tag, which got into a relevant change after the site got new uploader servers. https://forums.e-hentai.org/index.php?showtopic=#301426 | Ketsumedo Life | 4,375 The main change is that now all E-Hentai galleries that are in Japanese will have that tag (before it wasn't necessary, that's why the additional name). Better explained in the forum post. It is best to merge the tags since they're the same, plus, the "definition revised" is just a temporal indicator for the tag only meant for E-Hentai.

Not really by mistake, it's just a consequence of how this site works. It rips stuff from exhentai and grabs all the tags there. In any case, easiest merge ever.