I'm the author of the article, and throwing away the tickets was suggested many times by different people.

We had a pretty big discussion in #parrot about the value of this ticket set. People on the project plowed through the Trac database and closed tickets, and even with that we still hundreds that tracked all sorts of development. Many were bug reports, and many were effectively to-do items, and many were bug reports that had been resolved but still couldn't be closed for various reasons, such as needing an automated test to verify it.

It's nice to start over clean, but sometimes there's too much baby with the bathwater.