Thanks Hope, in fact I mis-spoke. I was on the move and wrote hastily.
Here is what John Fortescue wrote in British Campaigns in Flanders (1918) pp.361-362
[5th July] "On the morrow the leaders of the coalesced armies again met in conference at Waterloo, when it was decided that Clerfaye’s force should pass eastward towards Brussels, and that the army of the Allies should ultimately occupy a line from Antwerp, by Louvain, Wavre, and Gembloux, to Namur, but that until the 7th at any rate, the line in advance of Brussels, extending from Alost by Braine-e-Comte and Nivelles to Sombref, should be maintained. Ghent had already been evacuated, and accordingly on the next day Clerfaye’s force began its march to join Coburg, while Moira move to Alost and brought his troops for the first time under the Duke’s personal command. But meanwhile Jourdan was not inactive. On the 6th he attacked the whole line of the Austrians from B-l-C to Gembloux; and, though repulsed after hard fighting in the east, where a concentrated attack might have given him him possession of the Austrian line of comunications he succeeded in pushing Coburg’s right wing back from B-l-C and Nivelles to Waterloo. Thereupon Coburg warned the Duke of York that he must retire eastward and cancel the agreement made on the 5th…. On the 7th and 8th Jourdan renewed his attacks, directing the best of his strength against the Austrian left, which he forced back to Ramillies. He then immediately invested Namur; upon which Coburg, fearing to be cut off from the Meuse , ordered the whole of his army to retire upon Tirlemont… [and so on]"
So, there were attacks on a line 10km south of Mont St Jean on the 6th July, with the Austrian right pushed back to Waterloo. On 7th-8th the Austrian left was pushed back to Ramillies 40 km east of Waterloo. Whether there was a fight at Waterloo, I'm not so sure.
I don't think that's what the link claims. And I guess Ramillies was no more interesting to mention than Ligny...