I'm pretty sure these assets are not okay to resell as they are a part of unity's tutorial Survival Shooter, but you already know that, don't you?

https://learn.unity.com/project/survival-shooter-tutorial

Yes as i have build upon what the tutorial teaches and added onto the game creating what i believe is a better experience, the project was first started to see what can be achieved.

The assets have been allowed to use for a while now due to the age of the asset pack.