I believe the Ocado/Waitrose contract has come to an end - nothing to do with marital iunfidelity and all change, just business as usual.
As for working/middle/upper class shopping habits, I daresay everyone will continue to shop where they want to, regardless of how snobby/plebeian their choice of retailer. They will probably buy this thing here and that thing there, like the majority of real people do (as compared to the fantasy types who "always go to XXXX" or "always buy the cheapest" or "always buy the best". How restrictive that would be - they'd miss a lot!