I'm actually a tile shop owner and have been in the business for most of my life.
There are many types of thinset out there, make sure you buy a premium flex thinset.
Customs Mega lite or Tec Super flex. These both will securely bond to the substrate and allow for some movement/flex without breaking bond.
Also, make sure to remove the grout all the way around each piece you are removing, not doing so will damage the one next to it when removing it.
Tom