Ankit would have been the highest voted in the lot that was nominated, that is clear. So why would BB do something like this? Some reasons I can think of are that they want to maintain the narrative that Ankit is abla mard and needs Priyanka’s support. Another is so that they can call out Priyanka on WkV for taking this stand vs fighting with Sajid earlier when he saved Sumbul earlier. The situation was completey different because Sajid ne hi nominate kiya tha Sumbul ko and Priyanka did say she understands Gautam saving Soun, everybody made it into something else. Another reason I can think of for this is move is to divert the attention from the bullying the mandali did and also discussion of nomination that happened. Now since Ankit is safe, people will forget this incident and BB won’t have to punish all those involved in the discussion, thus saving Nimbu, Shiv, Archana.