Somewhat bemused by RG Newcastle, with its medical school being compared with OBU because it's allegedly simply a party uni of choice for less able students with means who want to party! You say we shouldn't make generalisations about 'posh' students or whatever and then you offer up that sweeping generalisation...
FWIW, it is worth noting state educated students are perfectly capable in and of themselves of being affluent, well heeled , well spoken, and privileged. The private state dichotomy is not that binary. The social inclusion data breaks all of the down a bit more finely.
I have noticed over the past six or seven years that ore students from my school are applying to Bristol and Exeter, partly because of the subject I teach being part of Exeter's offer, and Bristol and Exeter having good reputations for the literary subjects. I would add the caveat , though, that the students who have ended up going there are definitely not from disadvantaged families.
I wouldn't ever discourage anyone from going there , though. It seems an excellent uni, in a lovely part of the world. It was really only ease of access to transport home that put my north of London DC (both my own DS and students form my school) off considering it. The pastoral care and teaching are meant to be good. These unis are only going to become more diverse if fewer comprehensive school students from less well off backgrounds feel they want to go there. Many universities deploy various strategies to encourage this (Bristol is most well known for this, I'd say). The current cost of living crisis is having an impact on choices - especially for those form the least affluent backgrounds. There have been some well documented issues of problems in the recent past for state educated, especially Northern, students at Durham - I've never really heard of any similar issue or incident at Exeter.
We've been through this before , but one of the major reasons London students spread themselves out more geographically is their excellent transport links to just about everywhere. Draw lines on maps of where students come form to attend unis and you will find trainlines (cf Aberystwyth's large number of students from the West Midlands).