Sure, we will update it in the next update of Metronic.
We just tried the latest Tempus Dominus v6.7.7 and it worked well without any changes in the Metronic customization scss code for Tempus Dominus.
You just need to update it in core/html/tools/package.json as "@eonasdan/tempus-dominus": "^6.7.7" and try to run yarn task and recompile the assets with gulp.