Even though I do think Moltres should remain in S rank, the examples that you just provided aren't exactly rock solid. Durant does often run Rock Slide over Superpower for Fire-types, Escsvalier KOs Moltres with Return after Stealth Rock, and Tangrowth can nail it with Sleep Powder on the switch. Moltres should never ever even consider coming in on Sceptile, as it almost always carries HP Rock.
Moltres may still be S rank, but I feel that it's the worse than any of the others that are in the same rank. While spinning in RU is all well and good, just like Rapid Spin, Stealth Rock also only requires a single turn to be set up again. And Moltres IS quite easy to force out/revenge kill. However, I think that S rank is mainly justified becaude I cannot think of a Pokemon that causes more pain when it gets in safely, and getting in safely is all too likely due to the spinners.
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(16:08) <@skylight> CHERUB
(16:08) <@skylight> i will FUCK YOU
(17:20) <@skylight> ill luvdisc your ass