After the retirement of JFH under the 2010 SDSR, the reversion to STOVL in 2012 and the Pentagon's IOC decision in 2013, the UK carrier program was largely paced by airplane availability.
Since the USMC and AF IOC configurations (2B and 3i respectively) are not being supported for partners, the first operational export configuration (with the exception of Israel as always) is a post-IOT&E 3F.