I agree that the injury and his long time absence will have impact on Arsenal attacking but it won't be too serious for them. They have Martinelli, Saka, Odegaard and some great attacking midfielders who can cover the absence of Jesus. Moreover the style of Jesus is similar to attacking midfielder and he is not too good at a striker position.
I don't believe Tammy Abraham will leave Roma to join Arsenal. He might leave Roma and Italy, then return to Premier League but he might choose a bigger club than Arsenal.
Gabriel Jesus brought in that winning mentality into Arsenal from Man City and it helped propelled Arsenal attacking options
It should have an impact negatively I mean his absence because what he brings to the squad even without scoring can't be done by some players, to even say Nketiah, he is a back up option but will not be like Gabriel Jesus.
Why should Tammy Abraham leave Roma, he is scoring goals seeing full time game doesn't seat on the bench and has no problem with fans and coach, why should he leave, I see no reason for that