1) In all the previous seasons, in the last week we had 4 finalists, with one eliminated mid week and 3 remaining for the finale
2) Now lets look at this season - we have 4 weeks left and 8 contestants. Of these 2 (PM and Symmo) are guests, who will go anytime, so that leaves 6, by the end of this month, we will have 3 Aap Ke Farmaan and hence 3 will be evicted. So that leaves only 3 participants for last week.
3) But as per previous seasons, 4 are needed for the last week, so there is scope for one re-entry
4) Further, there has been no re-entry this season, PM's re-entry is as a guest only. Remember last season, both Dolly and Samir had come in.
5) So surely one participant will be back within the next 1 or 2 weeks.
6) Based on the popularity charts in BB site, it is clear that Mahek is the one who stands the greatest chance of coming back
So we arrive at the logical conclusion that Mahek's exit was scripted and that she will be back - based on popular demand 😉.
But why was she evicted in the first place - That too is clear, had she not been evicted, she would have won and brought a bad name to Sallu and hence sending her out and creating a furore in her favour and bringing her back is an easier option for BB 😛