Ah I thought you were naming BusyBox as an infringing work, not an infringed. Anyway, it does seem, as mentioned in the article, that if the copyright holder rereleases a similar work under a similar license, a past infringer gets a fresh shot, unless the author specifically publishes their revision history as a single work.

The point of the GPL really is about sharing, as the article suggests, not about punitive damages or post-violation injuctions. GPL-using authors do not want to prohibit infringers from future sharing, they want derived works published freely.

Much of the point of GPL and Free Software is about freedom for users, not making war against others. A past infringer gaining access to to code is not a loophole, it is part of the goal of the Free Software movement, which is unrestricted access for anyone to exploit software privately or to share it publicly (but not to allow public exploitation of non-shared code).