I don't think he would have been sacked regardless. Guardiola has a unique brand of football that isn't necessarily possible to convey in one season and I think their board recognise that. Look at Poch, I don't think we was properly playing as he demanded in his first season.
Next season is the acid test for him, and they still came third in the league - it wasn't exactly disastrous. And id be very worried about them next season, their forwards look ridiculously dangerous and if he adds a couple of defenders which is expected they could well be favourites.....
Guardiola did himself admit that if he'd been at a big club, instead of City, he would have been sacked.
Both Guardiola and Klopp have stated that their aim for next season is to add more attackers/goals to their sides, which should be good news if they continue to ignore their leaky defences.