You are saying a good thing that they have Reece James now. However I especially pointed that out because there is a possibility for César Azpilicueta could leave the team this summer.
I heard César Azpilicueta is interested in Barcelona. After Dani Alves retired it seemed that Barca did not have much money to buy new players at a younger age. But until now I have not heard any official news. At this age he can still make regular appearances in the EPL maybe for another two or three years. Chelsea may be able to buy other players like Jules Kounde, De Light, Niklas Sule, or Maxence Lacroix. They are young and have a longer playing term. They have abundant funds of course it doesn't matter if they want to buy new players.
Azpilicueta is a good player and he can be brought to fill Daniel Alves' place at Barcelona indeed. Maybe Azpilicueta isn't a young player now but I think that caring about the experience is more important when it comes to a left or right back. When it comes to signing a defender, I also know about Chelsea's interest in de Ligt too. But I don't think that they can sign him easily because Juventus see him as a very important part of the team. His current value is €70m too. They wouldn't like to sell him for a cheap price.