Yes! You can hide tracks and when you do, your changes are instant. There's no need to send out new email invitations.
To manage track visibility:
1. Click on RELEASES
2. Select a promo from the column on the left side of the page
3. On the right side of the page, scroll down until you see the track list
4. Click a toggle switch to change between the "hidden" and "showing" options
As an example, three tracks in the promo below are hidden.
*** Hidden tracks are not included in a promo's ZIP download. ***
Here is what the music listener will see: