Chaka is one name they used in very early development of TLK2, when cub was still male and latter they added him a sister, Shani, which overtook most of story from him and pushed him in background, so he was removed. And she got latter renamed once or twice too too.

The cub at the end is whoever you want it to be. Originally, since Disney did not plan on making a sequal, it was going to be a boy. Books were written saying it was a boy (I have one myself) until the lion king 2 came out. The cub looked different so this brought forth questions that Disney hoped people would ignore. The animators were lazy and careless and just re-designed the cub and presentation, but to some people they look too different to be re-designed. They should look similar in some way. So Disney said it was a genderless cub named "Fluffy" and left it at that. Then of course there was the one problem that got in the way, the six new adventures books. They said that Simba had a son called Kopa who was Kiara's older brother but got attacked by Zira, some say he died, others say he survived, but some people don't beleave he exists. Some people assumed that the cub is Kopa. And some people also say his original name was Chaka, or Simba had other sons and it was one of those, he just lost them all. So, since the cub is genderless you are free to take a side of who it is and say who you think it is. I personally am a Kopa fan but really there is no proof on who the cub is. Therefore it is in a way no one, allowing you to make it into someone, whoever you want
Sorry if I have confused you but I hope this helps in some way

Officially it is suppose to be Kiara, but there is arguing whether it really is Kiara or Kopa. Because cub at the end of TLK looks different than cub in beginning of TLK2.

Otherwise cub went through few names, first one being Fluffy, because developers at the time did not really have any plans for that cub, but they needed name for it.

Also in between fans also name Tanabi stuck around for some time.

Here is one image which gives some view on names cub had:
http://www.mylionking.com/forum/download/file.php?id=2&mode=view

It's Kiara. The sequel film's production uses that very cub in the official trailer as baby Kiara, and in an interview one of the animators literally said the cub is a queen, not a king. If you wish to ignore the sequel film, then the cub is no-one officially. Because the film itself leaves it nameless and genderless and then on the 1995 Laserdisc commentary track its creators call it Fluffy and still don't give it a gender, not even after the sequel film. So, the cub is Fluffy/Kiara.