On Thursday, March 1st, the Planning Commission unanimously supported the initiation of the proposed amendments to the General Plan, including the Central SoMa Plan. You can see their Resolution to Initiate here.
In terms of next steps, the Planning Commission has tentatively scheduled an informational hearing on March 22nd to consider the Plan's remaining issues. The soonest the Commission could act to approve the legislation would be March 29th, upon which time it would return to the Board of Supervisors for their deliberation.
The Central SoMa website has been updated with all of the relevant information.