Yes, the track will stay online on the album/EP after the single has been deleted.

And if you used the "Reuse your old tracks" function when uploading the album/EP, you can remove the single release without losing any play statistics from the track on the album/EP.

If you're not sure you used this function when uploading, check if the ISRC on the track is the same on both the single and the album. If that's the case, the answer is yes – you did use the "Reuse your old tracks" function, which means play statistics are syncing.