Every year, EAG London tends to be held in May/early June. In the UK, >90% of your degree comes from performance on final exams. These take place from May to June, and the norm is to study for at least a month. This means many talented UK undergraduates might not attend EAG London because they are too busy studying. Since travel is no longer reimbursed for the USA EAGs from the UK, this means that many talented undergraduates at UK schools cannot attend any EAGs.
For example, I currently attend Oxford, and think >30% of the most dedicated undergraduates here do not attend for exam reasons.
I'm pointing this out as I'm hoping this factor is considered when deciding dates in the future.
It's possible we should move the US event to May/June, though it's not obvious to me that that's the best move as finals still do have some weight there — I know it's less than the UK but I don't know that people's behavior is going to shift that much if an exam season is worth 50% of their grade vs 100%.
The US also has more potential attendees in general than the UK, which I think counts for something here. There are also just other downsides to shifting our conference schedule around too much, and most of our attendees aren't students anyway.