No the value isn't 0. It'll be still in the billions, or at least over 1B. If Roman agrees to hand the club over as he's now backed into a corner, some consortium will get the club for a hefty fee but still on the cheap compared to what Roman was asking for. The proceeds of the sale will then be the thing that is being sanctioned against Roman and not the club.
At least that's how I understand it. I don't think the government want to damage Chelsea any further than it needs to. It would suit all parties involved [except Roman perhaps] if the sale of the club is processed quickly.