Fixed to work with patch 6.3. Otherwise, there's only one change of note. There is now the option to ignore steam, so that Steam will not track your playtime. This option has mitigated the stuttering issue that some people experience after an hour or so of gameplay.
To be on the safe side, you should probably go into ~/.xlcore and delete the dalamud, dalamudAssets, devPlugins, installedPlugins, and runtime folders. There were major breaking changes to the dalamud plugin framework, so those files will need to be refreshed. Your pluginConfigs should be safe, though.