No they didn't allow 6,600 to vote, in NJ. The article says that: "and nearly 400 cast ballots". Not 6,600. Due to a glitch which briefly existed between June 2023 - June 2024, which will be investigated and was already fixed.

And the article acknowledged they clearly clicked that they were noncitizens and not eligible to vote. Hence it was not intentional. Hence it's pretty obvious you would never have gotten anything near 6600 voting. Adn again, the glitch was fixed in June 2024, before the Presidential election.