UPDATED
Repro:

1. Open Atom.
2. Open a bunch of tabs like 3-5
3. Open settings (on mac: cmd+,) (or ctrl + , on linux and windows)
4. Go to Packages and look for tabs package.
5. Change the settings to true and try to use the mouse wheel to scroll on the tabs.

Expected: works

Actual:
Windows: doesn't work
Mac: doesn't work
Linux: Works

Changing the setting in Packages -> Tabs in settings views doesn't do anything for any OS's

see screenshot:

macOS(same behavior as windows):

Ubuntu(even if you set to false it works):

Scrolling over tabs no longer changes the tab..

Tried on:
WIndows 10 Pro and Enterprise (x64)
Atom 1.7.2 and 1.8.0-beta2

With all the three possible settings: true, false and platform.