If you don't want to be political, that's totally fine and normal. This obsession we have with demanding artists be activists has not led to anything positive or productive. Things have just continued to get worse. Everywhere. In everything.
BUT, it's not exactly a secret who Macklemore is, the views he holds, or how they are incorporated in his act. I know Ed is an aloof guy with no phone, but given that they are personal friends, he should be the least surprised out of everyone. And this is literally what you have a team for.
"Oh hey, I know you were thinking of Macklemore as your opening act, but you have wanted to stay apolitical, and he is a very political person who is political in his act" is management 101.
So he ended up bringing this on himself by not doing basic due diligence and then getting him into a situation that was entirely predictable.
Ed Sheeran on why he doesn’t publicly discuss politics:
“My audience includes young people, often children, of all backgrounds. Those who come to my shows do not expect a political forum. I respect Macklemore's strength of purpose to stand up and shout for what he believes. However, there is room for multiple approaches to the same end: peace”