Yeah, they finished in 12th position, thus qualifying for the CL next season should be considered as progress. Chelsea have invested quite a lot of money on players, and i know that some people expect them to compete for the EPL title next season, but it isn't going to happen. Chelsea have players that are individually talented, but they need a coach that can get the best out of them as a team; Pochettino is a good coach, but he has to lower his expectations with the team for now, getting themselves back into the CL should be their priority.
I wonder how many top players will decide to remain in Chelsea next season. Most of them came to the club with the exception that they will be playing in the champions league and some of them came from top clubs. Chelsea have started their next season plan on a good note by bringing in an experienced coach but the have to be patient with him. His target shouldn't be to win any competition but to be in the top four positions. The disorganization in the Chelsea team will take a long time to reorganize. And Pochettino will be able to do the job.
That sounds more reasonable than aiming straight for the title. I mean it's not wrong for them to target all of that, but they also have to realize what state they started in. Obviously the first thing their new coach has to do is lay the foundations for the team, and it will surely take time for them to come back strong. We cannot ignore processes like this, and certainly will not be easy to do.
I'm not sure which players will leave Chelsea and which players will be part of the squad, including new players. What I know for sure they will make changes on a large scale of various things.