Arsenal has great players like Martinelli which can keep up the attacking pressure on other teams,of course the absence of such an important player like Gabriel Jesus can have negative effects during his absence for the Arsenal team but I also agree that the coach will just handle it fine.
The fact that Arsenal is clearly ahead in points gives them the serenity to take every single game with calm and caution and thus increasing their chances exponentially to continue to do great and keep winning game after game which in the end will award them hopefully the title.
Hopefully it won't be a worse impact after Gabriel Jesus' injury but with him Martinelli can still be relied on even though it's not the ideal place for him but Arteta will definitely change strategy again in managing their squad rotation after one important player is injured.
I haven't read the full news how long it will take Jesus to recover but what is certain is that everything will need to affect Jesus.
In this case, of course Arteta must be able to maintain his usual after the World Cup there are always changes in players from some of his squad, only Arteta can overcome this so that when the English league starts again it doesn't reduce their performance so far.
But for me it's enough that it won't drop drastically, but there will be a balance in this case.