This has been done before, in a way! @qwachansey investigated the holo patterns of the Illustrators and was able to conclude that the pkonno extra copies were almost certainly cut from the same sheets as the Illustrators awarded to winners (i.e. not printed in a basement). The tl,dr of the thread is that holo patterns on a sheet are not random and have identifiable repeating parts, you can match up those parts to tell which cards came from the same holo sheet.
With regards to the thread topic, I am skeptical of the idea that multiple high-end trophy cards have been printed recently. I think we’ve seen the best efforts of Akabane and others to fake trophies, and they were the very obviously questionable “test print” trophies. However, I wouldn’t touch any new-to-market trophy just in case. If it’s in a CGC case, I’m running for the hills.