supposedly because he wasn't doing a good enough job representing the brand.

Not sure what to make of that; or better, how was he failing to promote?  I follow him on Twitter and he tweets photos of himself (and others) at various functions, sportives, races, etc.  Also tweets quite a few photos of him working/riding with his sons and I think he runs, or is associated with, a school for cyclists who want to race (wielerschool?).  Also promotes his own exercise/spinning center.

In the majority of these photos he's posing with a Museeuw bike.  I get how it may come off like he's promoting himself and/or his own interests ahead of the bike company sometimes.  He does (or did) own 35% of Museeuw Bikes; but whether this is still true or not, you'd think he'd have a vested interest in the success of the brand bearing his name.

Understand that just tweeting photos isn't marketing/promoting per se, but seems he's always out in the public arena doing something related to cycling.  Given his popularity in Belgium, I'm sure he almost always draws a crowd and is a walking billboard with his surname appearing prominently.

Doping aside, he is my favorite classics guy and always thought of him as the quintessential "hardman".  A true "Flandrien".  Maybe with a bit of an ego, though.