Hey, so you know those 8 or so Nueva accounts? Well, I think I uncovered what their intended purpose was.
I believe they were not made by one person who kept forgetting their password, but was actually created by Roblox staff or someone working close with Roblox staff to have playtesting sessions at a school called "The Nueva School".
It appears that based on this forum archive those accounts were made for this Nueva School, absolutely confirming that Roblox was doing playtesting with this specific school (Why they chose this school I don't know). I checked the same thread on that forums archive and the ID of the OP for that thread is 78, which were made after the nueva accounts (interesting account name too).
It seems very likely that they were created during the playtests based off of that blog post, though not too sure about nueva8 in particular since the avatar picture provided is different to the others (possibly compromised?). I’d say it’s definitely worth mentioning on the page, though.