When I moved to work in Reading in 1992, I bought a map or two - of course. One of those was the 1:50,000 Landranger sheet 175 "Reading, Windsor, & surrounding area" (still under copyright). And exploring that (to prepare for looking for somewhere to live) I noticed a big feature just south of Bramley village, looking very like this from a 1:25,000 map of ca. 1948 on NLS. Note that Bramley village is there, but it's just a station, a pub, and three houses.

Obviously that's an ammunition store - the biggest in the country, in fact. It was in use in WW2 so its removal from maps seems normal; it's presence in 1948 does seem odd (though perhaps that map was not published at the time). Now it's still mostly in MoD use, apart from the railway connection and sidings there mainly built over with housing. It was not named on the map, but now it's called Bramley Training Area, but also hired out for non-military uses like filming.
Having seen that in 1992, I had a look (on the map) round Burghfield and was not surprised to see only fields and houses. When I turned up in Reading I was living at first in a company training centre, and on the wall was a mounted copy of the same map from the 1970s. There I was surprised to see ROF Burghfield clearly marked (here from the NLS's 1974 version):

On the same map, just south of Bramley, was only fields! So I don't think you should be looking for a consistent logical set of rules behind the decisions as to which ROFs are not being shown and which are at any time.