Another data point: Island Rum was working earlier today (2020-01-07), but after downloading an update, it now hangs on launch as others have described. 10.14.6 (Mojave) on two different systems. I tried downloading Island Rum from the eekstudio link, but it has the same hang-on-launch problem.
I can get CoH to run by using this command in the Terminal:
sh /Applications/coh/islandrum.sh
But after logging in the game complains about a version mismatch.