They don't log by default, but were legally compelled to do so in this instance.
Which is about as good as it gets. Unless you know of a reputable email provider that ignores court orders? (bit of an oxymoron)
I agree that ProtonMail and GMail are not the same in terms of privacy protections. But, the article implies that the bulk of advice provided in the article is somehow a guarantee to anonymity. A reader may easily assume that ProtonMail doesn't log any IP addresses at all based on that misconception. ProtonMail even used to claim exactly that in their sales page until that incident I linked to.
In fact, the article is the anti-thesis of itself. Blanket anonymity advice is the worst anonymity advice.
> Don't use Gmail -- use ProtonMail
"ProtonMail logged IP address of French activist after order by Swiss authorities" https://techcrunch.com/2021/09/06/protonmail-logged-ip-addre...