It just means that there will be the equivalent of infinite man-hours of barely-functional-intelligent-man to slog through code word by word and track how it affects all other code relation by relation.

It's not magic and it's not even better or even as good as a mid human, but it's something like infinite man-hours of that drudge work per hour per user.

That will find a lot in old code, and make it a lot easier to keep on finding every little thing right as it's created in new code.