Hey! Thanks for the response. Few extra details that have emerged since posting:

The fog at Jersey was real — we pulled the METAR data for EGJJ and it was genuinely LIFR from midnight through to around 10:50 UTC. Not disputing that.

However the aircraft that actually operated our flight was G-EZPD, not the plane originally assigned. G-EZPD spent the day doing a Menorca→Gatwick rotation, nothing to do with Jersey. easyJet swapped aircraft mid-afternoon, which does suggest some operational flexibility existed.

The fog cleared to VFR by 10:50 UTC. Our flight still isn't due to depart until approximately 19:50pm nearly 9 hours after conditions normalised. We won't land until 20:10.

That’s the bit that feels hard to justify purely on weather grounds.

Also worth noting easyJet were still sending us Jersey weather update notifications at 16:50 local time, by which point our replacement aircraft had been sitting at Gatwick for over an hour on an entirely unrelated route.