This is confirmed by many Belgian media and by LEGO via its online directory of official stores : A LEGO Store will open in Brussels in spring 2021.
Located at 117-119 Rue Neuve, this Flagship Store of 270 m2 will offer all the refinements usually present in the best-equipped LEGO Stores, including the possibility of creating a minifigure in your image and the presence of the 3D visualization system of the sets on the shelves of the store.
This will be the second official store in Belgium, with the other commercial space located in Wijnegem. LEGO is not communicating for the moment on a specific opening date for this new store, we can understand why.
(Thanks to Axel for the alert)