tldr: skip to past the bold text.

Okay, I control-effed my way through 21 years of amendments to the code of law, searching for modifications of Article 11.
Indeed, there were three modifications throughout the time:

  • 1997: increased max speed for motorcycles of class B by 5 km/h to 45 km/h
  • 2007: lower speed limits now apply for lorries above 3.5t instead of above 7.5t
  • 2018: coaches with seatbelts for all passengers may go up to 100 km/h

.oO(Sheesh, how long will it take legislators to use version control systems instead of an endless stream of paper documents with each lengthy “I, the king Albert decree that…” boilerplate and long-winded explanations what sentences in what articles have exactly been changed)

Anyway, after finding this out, I realised that these changes have already been incorporated in the Article 11 document, so yeah, I confirmed that the linked source has the most current information.
Also, giving it a second look, the 100 km/h limit for coaches on motorways and other dual carriageways is already in the table on the Default speed limits page. Sooo, this was all pretty much a waste of time.

Coming back to the topic,
we still need a source for the claim that cars+trailers may go 120 on the motorway. The law text is

Since I do not understand French and must rely on Google Translate, I was asking how trains de véhicules would be translated. And, does it include trailers, or not? (Google Translate just gives me “Vehicle trains”, whatever that is supposed to be)