If you have not changed your client to be 32bit, it should be running the 64bit version.
You can check this by going into the launcher settings menu (top right, first button) and checking if “Run clients with 64bit” is enabled.
I just checked with the launcher team, and they’ve confirmed that the launcher will currently stay as 32bit for the moment. There is little advantage to moving it to 64bit currently, although this may change in the future.