No, it was 4-5-1 because to be effective in a 4-3-3 you need players on the opposite flanks to their strongest foot.
To play 4-4-2, you need players on the same flank as their strongest foot.
this is not true
Really? Give me some examples of teams that have made it work with players on the wrong flanks in a 4-4-2 or the right flanks (so to speak) in a 4-3-3. I'm perfectly willing to be proven wrong, but all the evidence I've seen so far (Not just at Newcastle) indicates that some things work and some simply don't.
I don't disagree with your opinions on 4-4-2. It makes more sense to have people on their right side. Obviously they're not entirely comparable to us, but when Barcelona played their best football, Pedro was on the right of a 4-3-3. Sánchez is better for them on the right than he is on the left too. It's a lot more complex than that though and it depends on the player.
With a 4-3-3 I personally would prefer to have two players of the same footedness (not a word, I know) on the wings, so one can go outside and the other inside. It makes for a much more balanced attack imo.