Salah probably will not play a few matches due to the AFCON. If Liverpool starts to lose points now then it would be a good chance for them to get the top spot. Manchester City are also chasing now so things are getting very exciting.
Mo Salah won't miss too many games, there are only a few EPL games to be played in January, i think only 2 EPL games would be played this month, so Liverpool should be able to cope before Mo Salah returns from the AFCON. This is an opportunity for other attacking players to step up, the likes of Jota, Nunez and Gakpo, they have to start getting important goals, and if they do so, Salah won't be missed too much.
Having said that, Aston Villa do not have any chance of winning the league, though they have a chance of making it to Europe (CL or Europa League) next season. It is going to be a three horse race for the EPL title this season between Liverpool, Arsenal and City.