But the regulator guide is about GDPR. And it's consistent with what I wrote - GDPR law does not require consent for such cookies. So the regulator is ok with no consent.
Apart from GDPR law, there's also separate EU Cookie Legislation which was passed before GDPR. This regulation require clear user notification (not consent) that cookies are used. As far as I know (but I might be wrong, I don't follow it) this law is still in place and GDPR did not replace it. So that means you still need cookie notification banner (but not with "I accept" button but with "I understand").
No that's not true, look at article 5(3) of the directive, it exempts strictly necessary cookies as well (it doesn't reference cookies in particular but applies to all kinds of storage technologies instead): https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX...
I am not sure what exactly do you mean is not true. But in fact the article you linked says about pre-gdpr cookie consent. So it kind of contradicts what I said. But in practice to gather such consent it was allowed to say "if you don't consent, please disable cookies in your browser" and that's what I meant about "I understand" button. Regarding the exempt for this notification, I am not sure if CF cookies should be considered as strictly necessary.
Apart from GDPR law, there's also separate EU Cookie Legislation which was passed before GDPR. This regulation require clear user notification (not consent) that cookies are used. As far as I know (but I might be wrong, I don't follow it) this law is still in place and GDPR did not replace it. So that means you still need cookie notification banner (but not with "I accept" button but with "I understand").