I've been hit by schedule changes both ways on a DUB-PHL-xxx trip in December (I class, if it matters) that have increased the connection times from around 2 hours in each direction to nearly 6 hours or more.

There are no shorter options if I start in DUB. I thought I saw online that if the connection stretches to longer than 4 hours after a schedule change, they have some leeway to change the origin city within 300 miles. Ideally I'd switch the departure to LHR (280 miles from DUB), cancel my BA positioning flights, and end up with around 3 hour connections each way.

The agent I spoke to checked and said that while they could have done this within the same country, the rule doesn't apply if you're switching the origin to a different country. Is this correct, or should I HUACA? Thanks for your collective wisdom!