Inter Milan losing the UEFA Champions League trophy to PSG last season won't have any negative impact on their performance next season because when Manchester City defeated Inter Milan in UEFA Champions League final, Inter Milan won the Scudetto in the following season. I believe Inter Milan will compete in the Serie A next season as long as their players are fully fit to play in Serie A.
Inter Milan is a team that has great strikers but honestly they really lost focus last season after pulling a nice win against Barcelona but after then, they lost their zeal but we can't really judge them by their performance last season because i don't think they sold any of their key players and they have a new coach Cristian Chivu, he will develop tactics that the team will use and become formidable as they were last season till the ending part. Inter Milan will not only compete in the Serie A but even in the Champions League games they can still make a headway over there and probably make it to the finals since they could only end at semifinal stage last season.