As I understand it, Kopa originated from a series of children's books collectively called "The Lion King: Six New Adventures" that was available only briefly shortly after the original film's release, and under limited distribution and questionable licensing arrangements. Kopa appears in a couple of them. When it came time to produce "Simba's Pride", this series was for practical purposes disregarded as having any canonical value (retconned, some would say). Whether Kopa (and other things revealed in TLKSNA) should be considered canonical remains an ongoing debate among TLK fans, although most at least accept the parts that are non-conflicting with canonical sources. It is, for instance, the origin of Scar's real name (Taka) before getting his namesake scar, and the name of Mufasa and Scar's father (Ahadi). It should also be noted that the six stories of TLKSNA were by different authors and in some details have inconsistencies between them.
As I understand it, Kopa originated from a series of children's books collectively called "The Lion King: Six New Adventures" that was available only briefly shortly after the original film's release, and under limited distribution and questionable licensing arrangements. Kopa appears in a couple of them. When it came time to produce "Simba's Pride", this series was for practical purposes disregarded as having any canonical value (retconned, some would say). Whether Kopa (and other things revealed in TLKSNA) should be considered canonical remains an ongoing debate among TLK fans, although most at least accept the parts that are non-conflicting with canonical sources. It is, for instance, the origin of Scar's real name (Taka) before getting his namesake scar, and the name of Mufasa and Scar's father (Ahadi). It should also be noted that the six stories of TLKSNA were by different authors and in some details have inconsistencies between them.