As initially put, your point was completely obscured.
I suspect it would be overkill to have two wheelchair areas. 180s had three wheelchair spaces, two in standard and one in first. I never saw more than one space in use on the same train in the entire time they were in use by FGW/GWR. 'Entourage'? Presumably a whole one person. Or are devious people stealing wheelchairs, pretending to be disabled and then bringing the entire family along for bargain trip in first?
If the DfT hadn't insisted on putting a super-dooper space-eating kitchen in all the five-car sets something else could have happened, but that's a moot point now. Once the nine-car sets start running, a lot of services will have wheelchair spaces in standard, so this 'issue' will not be one on all those services anyway.
Unless someone has placed a buggy directly across the doors into the coach - which is a probably an offence under some bylaw or other and a safety hazard in any case - I fail to see how that prevents a trolley getting through.
Not sure the person in question illustrates anything, other than wanting to stand in a vestibule between Oxford and Hanborough all the time, if he is, as I strongly suspect, the person who posted this at the GW Passengers' Forum
http://www.firstgreatwestern.info/coffeeshop/index.php?topic=18792.300
His (and others') choice to stand - I assume in the past he would have posted himself in the area around the disabled toilet in coach E on a Class 180, as the rest of the vestibules on those trains and on Mk3s are much the same size as an 800. How dare the Hitachi designers try to maximise seating capacity...
He could always stand in another one - probably all of his very own - back down the train and walk up approaching Hanborough. Some of us manage to walk up a train at other stations with short platforms and if you are doing a regular commute you can hardly claim to be unfamiliar with the journey time (eight minutes OXF-HND)/where you are on the route. In any case, the platform at Hanborough will be lengthened to seven-car length along with others on the Cotswold Line later this year, so he will soon be spoiled for choice of vestibules, whether on a five-car or a nine-car set.