Have you already removed the existing tiles and noticed that it took some of the drywall with it? Do you have large gaps or holes in your drywall and need to know if it's needs to be repaired before the new tile installation?
Typically a remodel tile project involves the removal of the existing tile or other material. The removal process can damage the drywall depending on well it's bonded. But how much damage can be overlooked without the need for repair before the new tile is installed?
It depends on how extensive the damage to the drywall is and the size of the new tile. You need to check the overall condition of the drywall by looking for holes and loose areas that are no longer fastened to the wood studs.
If you have minor holes throughout including some loose drywall, but are considering a large tile, you may be able to remove any loose areas to allow the new tile to bond to a solid material.