As a cross fan, I hope they'll never do that. The cross needs them and I hope Boom will consider coming back to World Cup and/or Superprestige events, soon. And why not Sagan, as well.
Stybar is highly underrated on the road though. Good sprint but can also decently climb. I think he was top10 in the Giro delle Regioni a few years back. But now he rather focuses on MTB in summer.
Pauwels is also a great climber (showed it in Lerida 2007) and has a good sprint.
Why on earth should pro riders of 24 not be allowed to 2.2? Only in Belgium are the pros kept from them and the crossers did not appreciate that. They have to ride in summer and stage races are the best preparation for the winters.
Albert was 5th in last year's queen stage of the Tour of Belgium and was really strong in the climbs (16th in the GC).