No, a DQ is something WWE should not consider in any scenario. It looks increasingly likely that Taker will have to work through an injury at Mania, as I doubt he'll be fully recovered from his surgery in time.
The way to do this is have a triple threat, or a fatal 4 way. That way, WWE decrease the workload for Taker, as he won't have to do too much work. I see a scenario where 2 or 3 people come out saying that they want to have a shot at the streak this year, then have a series of matches between these guys, but neither comes out on top in these matches (a best of 3 falls or something, but neither guy gets the winning pinfall). Eventually T-Lo announces that the 2/3 guys will both/all face Taker at Mania. You would have the big draw of Taker facing the worst odds ever in his Mania match, but at the same time, he doesn't have to work a full match, thus accommodating his injury. Obviously, Taker wins the match