Anecdotally, and perhaps ironically, they were right, I am dyslexic, and I definitely do perceive letters as permuted quite often. The second link really chuffs me because it's clearly a non-dyslexic person openly speculating as if they're authoritative, but this theory of "3d processing" words jives with neither other literature about dyslexia, nor my own experience. I'm pretty sure this is just someone showerthinking about a disorder. The errors I make are pretty incompatible with seeing whole words from the wrong "angle"; letters are switched, sometimes even between adjacent words (I might see "angle" as "angel", or "and rain" as "an drain"), similar graphs are misread as each other (the classic example is [b / d / p / q], sometimes also g depending on font; [w / m / E], [e / a], [T / L], so on), words can be entirely displaced elsewhere in a sentence...

So yes, like, I definitely do see some letters backwards or upside down or mirrored, etc.