He’s been brought in to work with this expensive squad, there is no rebuild needed. It’s either work with this or he’s gone
Our midfield is definitely in need of a rebuild though.
Kante is on his last legs and Jorginho has been on a bit of a decline as well, both players also have their contracts up next summer and I don't think either of them will get extended. Then we have the loanee Zakaria who was only really brought in as an emergency option for the congested season and is not someone the club are planning for the future with. Kovacic is quality but has been quite injury prone for years and the question remains is he a player we can fully rely on over a long season? Loftus-Cheek has shown he's a decent squad option to have but as much as I like the lad I don't think he's good enough to be a regular starter in a team aiming for the top places.
Out of Kante, Jorginho, Zakaria, Kovacic and RLC at the moment I would only expect the last two to still be at the club next season and even then RLC should not be in a key role.
As for other areas Silva needs replacing next year, Azpi should have been let go and replaced this year already and up front Aubameyang at his age is only a short term fix and hasn't been good enough anyway. Pulisic and Ziyech have been underperforming under three different managers so far and both will probably get sold as soon as we can find a buyer, which should be getting easier with their contracts running down. I would also go as far as saying Havertz should be sold next year too if we can find a buyer for a decent enough value.
Maybe filling all of those positions within a year is not realistic but getting a new CB, a decent backup for James, a couple of starting quality midfielders and a couple new forwards should be the starting point going into the next few transfer windows. Whether that qualifies as a 'rebuild' or not is down to your interpretation of the word but those are all positions we definitely need to fill sooner rather than later.