But I too think that he could do okay (so at least top-10) if he where to race Roubaix this week, so without additional specific preparations wrt to weight. In the right circumstances, I think he could possibly even get on the podium.
I think it'd be wise for him to race Roubaix first without tailoring his prep for it, so just to test himself, get some experience and see how well he can do with his current weight. He could have a spring next year where he only races the monuments (so no E3 or Amstel) with the same prep as for this year. I hope he does that, and I think he would still challenge for the win in Liège.