I could be wrong but my bet is, they will continue with the name Linkin Park but will not take a new singer. I feel like even if they revived some legendary singer from the dead who could sing the songs to a perfection, he would still get booed off stage. That is how much people loved Chester and they would see replacing him as a spit to the face. At least right now and near future, i don't think people don't want to hear the old tracks sung by another singer. It would feel like "too soon" and weird. Playback for Chestert's vocals feels the correct thing to do for the moment to pay a tribute.