tl;dr Either way is fine.
When making ice cream- your quest is to bind up water. Water crystallizes and makes ice cream icy instead of creamy. There are a lot of ways to keep water from freezing in ice cream from reducing the volume of water in the mix, to using natural antifreezes, to binding the water up with gums or starches.
Sugar loves water. The water will eagerly hook up with sugar and won't be able to freeze.
If you macerate your cherries two things will happen-
1- Water will be drawn out of the cherries and
2- The water that is left in them will be saturated with sugar and slower to freeze.
The result is that the cherries will be softer, sweeter (of course), be slightly more concentrated, and not freeze solid.
If you don't macerate them then they will be little chunks for cherry ice.
Both ways are perfectly tasty and I've had ice creams that do it either way. It just depends what you want to make.