That's not the case in any of the examples and it's impossible for this to happen if you don't use that account! How could Coinbase report something to the IRS when your account is inactive and you don't sell anything? Besides, there is not a thing of "may" Coinbase does notify the IRS, that's like a feature, they report everything .
The thing is pretty clear, you sell coins on the exchange then you need to fill the tax form with these, the case you've mentioned first is about an incorrect report made by Coinbase over double transactions when one of those was actually canceled. The second one is that the guy did trade but because he claims his gains are zero he didn't file any tax form, yet she should have mentioned that when Coinbase reported it showed at 192k in volume, the author itself doesn't help at all, going down through his own comments, this comment is probably the best:
Now assuming there is indeed a fault over at Coinbase adding transactions to your account even when you don't trade then there is little to help you with keeping zero funds on it, the errors could still happen.
Leaving coins from 2017 on Coinbase and not even once login in to check what's happening? Lol...