Ok, you are right, I completely missed how this used to work.
Yes, you are right. It was enabled at the time that we removed the feature. (We had disabled it on some scenarios for our hosting.)
And on closer look, there are a few niceties in the bootstrap mode that we should keep, marking the first admin as a moderator and granting TL1 to the first group of new users stand out to me as desirable features.