Comment by Dwedit

Seems like this idea solves a different problem than signed timestamps. You have access to not only the current random numbers, but also any random number from the past (as long as someone somewhere wrote it down). I just don't quite get what this could solve if you can either use a current number or an old number. Just not a future number because they're not around yet.

Embedding a public random number also doesn't resist tampering, unlike signed timestamps.