If a coder has seemingly abandoned their plugin, and I've fixed it for 4.0

[Zachery]

You guys really aren't paying attention. We aren't talking about emailing a coder and asking permission; we're talking about coders that completely disappear. Dead, perhaps, or changed emails and no longer care a whit about vbulletin or mods they wrote here.

Its their code, doesn't matter if they're dead or abandoned the site, its their code. Without their permission you cannot relrelease their workd, period, end of story.