The author of the article is uninformed or lying. I would guess they just don’t know what they’re talking about but never rule out malice.
https://answers.scottsenglish.com/discussion/209/is-correct-....
> In the TOEIC and TOEFL, the examiners are reading for content, and not specifically spelling mistakes. Your score will be lower if you misspell a word that is written in the question, or if you misspell the same word in different ways. As on the IELTS, your meaning must be clear.
https://www.prepadviser.com/toefl/important-spelling-toefl-v...
> How Important is Spelling in TOEFL?
> The answer to this question is actually really easy – it’s not very important.
> This does not mean that spelling is completely unimportant for TOEFL essays, but it’s only one part, and it is not one of the most important aspects. Most of the time, spelling does not cause any problems. The most important areas to pay attention to are usually others: structure, grammar, vocabulary, details, etc.
Its very hard to keep British and American English apart as we don't know in many cases who wrote something on the Internet and we also read and listen to shows and YouTube videos from various places.
As someone who had trouble learning English in class and ended up self-teaching using the Internet and reading English literature, I would have no hope of passing that test. Additionally I wouldn't be able to explain English grammar for the life of me.
However being multi-lingual and learning from multiple sources appears to do wonders for one's vocabulary - in pure vocabulary tests I tend to outscore native speakers.