The performance of Chelsea by next season is somthing I cannot actually predict. I mean it is easy to say that Chelsea will perform well by next season. But also consider that almost every club wants to perform well also. If you wish to talk about the top 5. What is the possibility that Chelsea can displace;
Manchester city;
Arsenal;
Manchester United;
Liverpool
And not to talk about Newcastle and Co from the top 4. It will be difficult to Chelsea. If Poch can take Chelsea to Europa it should be considered a success.
I think that the first four teams you have mentioned have a big potential to end in top 4 next season. The first three have already done it but Liverpool have had serious problems so far. Liverpool couldn't make it to top four surprisingly and left their place to Newcastle. But hopefully Klopp will figure out a way. Mane's absence was also a serious factor in this but this isn't an issue that can't be solved of course. They already started to get more consistent results while we were getting close to the end of the season.
I think Newcastle's consistency will depend on how good transfers they will make this summer. Thinking all about these Chelsea's job is really difficult but not impossible. Their main target should be top 4 before anything else.
Yea, the only club that Chelsea can boast to displace from the top 4 is Newcastle United and this can be possible if Newcastle United refuses to reinforce their team. And I think we all know that it is impossible for Newcastle not to reinforce their team. So it will really be tough for Chelsea next season.
The only advantage that Chelsea will have over Newcastle and others in top 4 is that Chelsea will not be playing in European competitions next season, so they will have enough rest time and few game time. This can enable them concentrate on EPL title chase.