I don't think Pep Guardiola will leave just because he has four defeats with his work. Every team can be defeated, there is no team that cannot be defeated. Manchester City can be defeated too. The important thing is to trust Guardiola a lot considering his past successes. Even if they don't become champions this year, Guardiola himself knows best where to intervene for next year. That's why I think he shouldn't leave the team. If he leaves the team, Manchester City will be the loser. I don't see a better manager in the world right now.
Premier League has 11 match days so far and Manchester City are at a second position, not too bad, and if we see point difference with a club at first position Liverpool, it's only 5 points.
Premier League table shows that even Manchester City got some bad results recently, they are 4 points more than 4 clubs behind, Arsenal, Chelsea, Nottingham Forest and Brighton. The season does not end in November and with 5 point difference, chance for Manchester City is not too small. They can flip Liverpool any time in rest of season so there is no reason for Pep Guardiola to leave the club now.