Since 1.14.6 Wesnoth for macOS uses app sandboxing feature, which means Wesnoth has a new location for saves, addons, maps and preferences. Everything will be migrated to the new location on first run.
A: No, it won't.
A: Probably not. Every dev version of Wesnoth for macOS since this commit will automatically link the old saves location to the new one. So you shouldn't be able to recognize the change.
A: If you compile Wesnoth from source, then it won't affect you. If not, then you will probably be interested in creating a symlink from the old location to the new one. See the question below for steps.
A: Your saves were moved to the new location. For backward compatibility you can use the steps below.
- Open terminal (https://www.wikihow.com/Open-a-Terminal-Window-in-Mac)
- Copy and Paste this command inside terminal window:
ln -s ~/Library/Containers/org.wesnoth.Wesnoth/Data/Library/Application\ Support/Wesnoth_1.14/ ~/Library/Application\ Support/Wesnoth_1.14/
- Hit Enter