No it couldn't be, don't be silly. Dieselgate was a systemic industry-wide problem, with most manufacturers involved to at least some extent, and not just car makers but also the supply chain (for whatever reason, in the popular imagining it was mostly just VW, but in reality the corruption was far more widespread). Even if the allegations are correct, this is, at worst, just a single manufacturer; no reason to think that it's more widespread.