French orthographic and grammatical history has been non-linear and it's not uncommon for texts from the 16th century to be harder to read than from the 13th c., while at the same time the Medieval texts have sometimes confusing syntax for modern French speakers because of the declensions. For example in the sample given by the article :

    Mauuoisement li quiens Bertram ad dit

It's not something that a modern native French speaker would understand at first sight. Li quiens (or li cuens in more standard Old French) is the cas sujet of "count", the form that survived in French is the cas régime, le conte.