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.
