I am unsure whether or not this would result in the same level of wearout. I could imagine it depends on the specific implementation of the mining software/firmware and how it handles stopping the mining process. One thing that's different for sure is that fans can keep running a bit longer for cool down and that the control board will not suddenly turn on and off all the time. Given that hash boars are obviously the most important part of the miner this question is something I would really like to get to the bottom of. I'd probably have to ask a hardware engineer or developers of the firmware.
I am glad we both agree that the hash boards are the main focus here, and this is why i mentioned above I don't see how both ways differ, someone mentioned that the sudden change of temperature will negatively affect the solder/themal epoxy, I can't confirm/deny that but if that was true, then still both ways will cause a sudden change in temps, in fact, leaving the fans on will make it even worse.
One thing I can tell you for sure is that if the miner isn't generating heat and the fans still spin and they are in wet weather with high humidity you will be in big trouble, this is probably why Bitmain's firmware keeps the hash boards on (generating heat) even if they disconnect from the internet, something that almost all custom firmware devs changed thinking it's a good way to save on the power bill, which makes sense for someone who has a perfect environment to sustain such a thing.
On a side but related note, Whatsminer community in this forum is rather small, it's only a few of us around, you might want to check the telegram community as it's pretty much a lot more active.
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