you're right. bad wording the point is 3.142 is not pi. so the "binary" code cant be pi.
Eh, maybe. I'll grant you that an actual binary representation of Pi would look different e.g. 3142 in binary is 110001000110, and that what we seem to have is four separate binary numbers counting out 3, 1, 4, 2 which are the decimal digits of Pi. So if it is Pi, it's a bit anthropocentric, and we might not expect that from a real alien message. OTOH the message is actually from FDev and maybe it's a bit less alien than it's supposed to be (if the UP/UA are even non-human) or, for an in-lore explanation, maybe they're intentionally using a number base we know to communicate with greater ease.
OTOH I could be convinced by the idea they're numerical indices too.
Right now it could be either. "Not Pi" requires slightly fewer assumptions which is good, but the fact it appears to be a circle sort of suggests Pi might be a thing you'd see.
Until it's decoded, I think it's hard to say with confidence that it's no Pi.