I think that's vice versa. Although there are those who claim that GF has nothing to do with the fires of Halloween/samhain, the timeing is suspicious. What better way of carrying on an ancient and enjoyable custom than disguising it as something the powers that be just have to support. Ie, Christians don't celebrate samhain - O look, here's All Saints' Day at just the same time, and All Souls' Day as well! Wouldn't it be nice to light bonfires for them?
Protestants don't celebrate All Saints and All Souls, especially the latter, as you cannot pray for the dead who are gone where their lives determined, for ever. Goodness me, here's a valid reason to celebrate the end of a Catholic conspiracy! Shall we celebrate that by rolling burning barrels down the hill? Too?