Norfolk Royal I don't share Green's rather world weary pessimism about this. Not surprisingly really as Norwich based Royals fans (pop 1) can now hop onto Crossrail at Liverpool St and be in Reading in a mere trice.
I think it's quite a big deal being on the tube map, albeit as Green says, but surely in his example the district line didn't actually go to Southend in any case, whereas Crossrail, or the Elizabeth Line as it is called, does go to Reading which is a different ballpark.
Hard as it is to believe District line trains used to run all the way from Windsor to Southend, in the 1930s. Crossrail is nothing new in that regard (indeed Thameslink has been providing a through service for North/South journeys through the capital for decades)
But yes I take the point - it is a big deal for Reading and has almost certainly contributed to the recent house price rise in the area.