We just sailed on RCL, and they do have RFID wristbands. They charged for them, which, ew, so I didn't get one, but I did notice a lot of people having a lot of problems with them. You still needed your card to disembark and reboard the ship, but you needed your license as well for that, so I assume you could just grab both when you went to grab one.
RCL also didn't have "lanyard culture" like
DCL - seriously, *everybody* on DCL wears a lanyard, but I only saw a few on RCL. Which means people on DCL with lanyards look normal, and people on RCL with lanyards look like dorks