It seems to me that with rare exceptions there's a bit of confusion about this topic.
The map must be analized as it is. And for what I can see, the current map doesn't have elements on it that glorify the British soldiers in a different way than a historical point of view. The legend simply mentions that the soldiers received a medal, this is a fact, not taking a postion or change the reality of things. I do not see anything offensive in this.
Similarly, the map doesn't denigrate the Zulu troops using any sort of racist term or trying to diminish their effort in the battle.
My role is to look at the map, not the opinions of those who drew the map.
For me everyone is free to have their own opinions, the important thing is that everyone keep the opinion for themselves and that they don't use the map as a "manifesto" to sponsor those opinions.
The map, as it is now, it's just the story of what happened at that time, so it's good in that way. Maybe that phrase in the legend can be rephrased or removed, but this is not a case where I can draw a line.
Colonialism wasn't certainly a good thing, but it's part of history. It can be represented on a map, just it's necessary to represent it in the right way without making a map that says "I'm a supporter of this side". This is history, and this is how historical maps must work. History can only be told, not changed (sorry if someone here is a fan of counterfactualism, that is my opinion is not bad but just a good way to start a discussion with friends)
I read in this thread that some people is arguing about a koontz post or about how much time has passed or trying to make a comparison with the swastika symbol. All those things are totally different concepts and topic and they are not related with the current one.
The concept is not based on how much time has passed, what are you ideas or what faction you want to represent. If we want to draw a line, the line must stay where the common sense lies. If your representation goes over the common sense, then expect that someone in blue will come to draw a line.
Swastika (again

) is a different topic and as I already said any discussion about a possible use is useless. We can agree or not about the use, but this is a case in which we can argue for months but nothing will change.It's just a rule of this site. You can't use it here.
I hope that this make clear because this map has reached the Beta stage with that text on it.
Nobodies