Westy,
Typhoon has an internal cannon installation. As a last minute cost-saving measure the RAF decided that it didn't want or need the weapon.
Its decision was so last minute that the aircraft are still being delivered with an operable cannon fitted, but the weapon will not be supported in service, will not be serviced (except insofar as is necessary for flight safety) and ammunition, etc. will not be procured.
Removing the weapon altogether would have required the design and clearance of a suitable piece of ballast, and would have impacted on timescales that are already 'stretched'. The weapon may be designed out of Tranche 3 Typhoons for the RAF, but is already part of Tranche 2, I believe.
The other partner nations (and the export customer) are being less parsimonious, and a service gun firing clearance (the manufacturers now have one) is just around the corner.