Hello Blackfox,
It could if Britain formally guaranteed its independence - perhaps even with a British garrison.
The Talleyrand Plan seems unlikely for the reasons it didn't happen, i.e., distrust of France in general and Talleyrand in particular. But it's not completely impossible. If the Hundred Days doesn't happen . . . or if ethnic resentments are stronger. . . carving up the baby wasn't completely unlikely.
The butterflies would be profound. Prussia would have a far larger front on which to attack in 1870, but the end result - French defeat - would be the same. The question would be whether Moltke would demand territorial concessions along the Meuse to complement Alsace Lorraine. My guess is not - Bismark was keen to keep the number of Francophones in the Empire to a minimum. At worst, perhaps the high ground on the west bank of the river around Liege and Eben.
The real departure, of course, would be World War I. The Germans no longer have any Belgian neutrality to violate in attacking across the plains of Belgium, while conversely, the French have a much longer border to fortify. This would have major impacts on the war planning of both states. British intervention seems less likely in such a circumstance, but still not impossible. Grey would have to work harder, however, to find a formal casus belli to justify his real interest, which was preventing German domination of France.