Actually, it’s not a paradox *yet,* just a loop. Confusing, but internally consistent. The main thing about a paradox is that it *isn’t* consistent – the old thing about going back in time to kill your grandfather, so you’d never be born to go back in time and kill him, so he’d still be alive, and so would you, and you’d go back in time…
Now a *real* paradox would be if, for some reason, John Fox *hadn’t* saved Iris… then Wally never would have gone to Central City and met the Flash, and you have either the Flash line ending with Barry or being picked up by someone else… who might have found a different solution to Mota (50th Anniversary Special) that wouldn’t have left him slowly turning into Radioactive Man over 700 years to reappear in John Fox’s time and lead to his gaining super-speed.
Hmmm… if that happened, then he wouldn’t even have the *chance* to help rescue Iris, and that future would remain intact. So I guess it technically wouldn’t be a paradox either. Aargh!
No wonder Wally gets a headache whenever he deals with time travel!