To start with: Walloons don't want further federalisation.

That's what I meant. They don't want further federalisation, the Flemish parties do. At the same time there is the struggle about the B-H-V region. The Walloons probably (and justifiably) feel that if they give up one bit, the Flemish will just come back in 4 to 8 years asking for more. But the Walloons can't expect not to give away anything this round, considering the outcome of the elections, and B-H-V is the lesser of the two chips.