Tim,
There may well be some surplus Typhoons because the 232 aircraft figure was predicated on supporting an active fleet of 137 aircraft through to the planned OSD. That 137 aircraft fleet was in turn based on a seven squadron force, plus and OCU and an OEU.
It now seems unlikely that there will be seven squadrons, with the elimination of Leeming, though there may still be six.
There won't be that many spare jets. Perhaps backing out of JSF would allow us to buy a few more - or a few Gripens.