This was over 20 years ago, and the machine itself would have been about 20 years old at that point. At that time, it would have been the norm to dispose of such a machine in such a manner. It was certainly too big to grab for the collection of vintage personal computers I had at the time![1] (To be more specific, it was a disorderly pile of pieces on a dock where equipment was frequently left to be disposed of.)

Of course, I can't be certain it was the machine Gosling used. I don't know how many PDP's the university had. My recollections are also sufficiently vague that I don't remember the exact model, just that it was a PDP composed of many boards. Anyway, the bit about Gosling possibly using it was just a fancy I had while listening to the interview.

[1] Calling those personal computers vintage seems weird now. None of those computers would have been older than 15 years at that point in time, but a 1982 computer would have less in common with a 1997 computer than a 2005 computer with a 2020 one.