In this case Man City is the party who benefits because Kevin de Bruyne return coincides with Mo Salah long absence. And for the party that is slightly disadvantaged, Liverpool needs to be able to overcome Mo Salah absence in any way. In the last match Nunez was Liverpool substitute and savior to maintain the point difference from Man City. But because 1 month is quite a long time it means that there are 3 to 4 matches that have to be played without Mo Salah and this is clearly not something that is easy for Liverpool to go through. The 5 point difference is not the problem but Liverpool consistency is at stake without a capable striker. I don't doubt Liverpool players but Mo Salah presence is vital in every victory they achieve.
indeed a loss for Liverpool. but it seems like Klopp doesn't want to make it a burden for the team to face several opponents. and several matches seem to have been successfully passed. they won 0-2 from Arsenal. they won 2-1 from Fulham. and finally won 0-4 against Bournemouth.
Klopp still has several player options on the front line with a combination of Gakpo, Nunez, Jota, Luis Diaz, and Elliot. Even though Salah is very important for the team, when he can't play then Klopp has to maximize the existing players. They cannot give up City's pursuit, which still has 1 match.
I was surprised that Bournemouth were easily beaten by Liverpool. I was expecting Bournemouth to give Liverpool a hard time before Liverpool could defeat them. Liverpool has shown they can still win their matches even though they are not with Salah.