the shurikens are 100% serious and he was going all out. Trying to deny that is ridiculous, why the **** would sonic held it against saitama? Bro, just stop being a nuisance and a denier, please, i beg you. Everyone here understands that you dont like Tatsumaki, but you literally wont do anything with those kind of arguments.
And yes, those are the SAME SONIC, theres nothing implying that he became faster, even if he did, he only did became unquantifiable faster than his past self, the same key. That said, Tatsumaki would still scales, or outscales.