Feature Request

• [ x ] Yes, I reviewed the contribution guidelines.

If I'm understanding right the --url flag is ignored when doing a wp cache flush. but no notice is given saying the flag is being ignored.

Is it feasible to update cache-command to clear caches for only subsite
e.g. when below command is run
wp cache flush --url=www.multisite.com/subsite
only flush www.multisite.com/subsite but don't affect caches on www.multisite.com/ or www.multisite.com/other-subsite

If not, maybe a notice that the flag is being ignored would be helpful.