And would the French change their strategy in time?
They were set on an offensive into Lorraine, and would be delighted at a German swing to the right, since the further west their line extended, the thinner they would (supposedly) be in Lorraine, and the easier for the French Army to break through there. By the time they realised that it wasn't going to be that way, it could well be too late.
I doubt it since we're talking days here and the big 2 surprises to the French were the depth of the wheel into Belgium and the deployment of Reserve divisions in this offensive. I assume Belgium's permission would occur on Aug 3 instead of OTL's denial and the Germans would advance pretty much in line with what France thought for a few days at least, allowing both French and German mobilisation to occur as per OTL and the Battle of Mulhouse also to occur as per OTL. I think the French would conclude that the Germans might go a bit deeper and faster than pre-war expectations as a result of the Belgian decision.
The OTL Plan 17's offensive into Lorraine would at least begin on the 14th as per OTL, but I think by then the French would begin to sense the depth and size of the penetration, but as per their OTL pre-war strategy would push on in order to cut in under the German wheel. By this time I think some Germans would be travelling into Belgium itself by train.
If by the time of OTL French Ardennes offensive on 21 Aug I think it would be well known that the Germans were deep in Belgium and this offensive would be changed to something resembling OTL Battle of Charleroi that occurred at the same time. By this time the French are screwed as the Germans have had over 2 weeks of unhindered road movement and maybe 2 weeks of unhindered rail movement, and if the ad-hoc rail movement surrounding the Battle of Tannenburg are any indication Germans Corps and Divisions will be deep into Belgium before the French even realise there's a problem.
IOTL once the French realised there was a problem they shifted west in about 2 weeks, so I think basically the Germans easily win the Race to the Sea, probably capture Paris but as per OTL will struggle to encircle and destroy an Army Tannenburg style.