Scotland's most famous victory over the "auld enemy'
The Celtic fringe assert their independence and evoke the Battle of Bannockburn, Battle of Cadfan, and the Irish rebellion. The term 'historic agreement' is loaded and suggests a turning point. The Yalta Conference was a historical agreement and established the re-organization of post World War II Europe.
The BOA's semantics could deliberately be construed by the Celtic counterparts hereon in a reduced role as mere rubberstamps for the English FA. The fear is FIFA might begin to see less daylight between the national bodies which could jeopardize future participation in the Euro and World Cup. There lies the backlash.
This after all is football; not cycling, curling, or show jumping. Scotland still celebrates its 1967 victory over England a year after their southern neighbours won the World Cup. The BOA in consultation with the FA came up with team GB for the 2012 Olympics but should have used more calibrated language even as they hold the legal upperhand.
For their part the Scottish, Wales, and Northern Ireland FA are merely posturing but in reality their advisories could dampen any footballer's enthusiasm to join the united team. With 15 under 23 players allowed and three others of any age, that leaves Gareth Bale as the only non English player with a realistic chance of representation. Which is why they probably wanted team GB in the first place.