It will be the "Finstock" of the Chiltern line, withering on with no-one having the nerve to close it.
Hopefully, they'll just shove the franchise commitment calls to silly o clock hours to close it by stealth. The only reason it has so many passengers now, is that it acts as a mini parkway for Oxford, Water Eaton is basically replacing it.
In this day and age of constant fare hikes, you cannot justify keeping these halts open, pretending we're still in the 1950s. See also: Cotswold halts train!
Given Finstock has less than 2,000 entries and exits a year and Islip already has over 29,000 I think that's a pretty poor comparison. And remember the current service is very slow, on account of the poor infrastructure. It'll be much faster one the upgrade is finished.
And what about that "halt" at Parson St, which has gone from 4,000 to 78,000 in the last 10 years. Would you have closed that one in 2001?
As regards Water Eaton Parkway, unless I'm completely mistaken, I thought the point was to provide a Parkway for those travelling towards London, not for Oxford commuters. In which case, it certainly wouldn't be replacing Islip in serving that purpose (not that it does anyway according to II).