A lot of companies do this
A lot of companies do this, not only airlines but banks, hotels, news publications, etc often use a whole heap of third party trackers. This is often something decided by non-technical people who have received a sales pitch from those tracking companies, and who then decide to use them without fully understanding the technical implications.
On the topic of Emirates, they have had other interesting issues in the past. E.g. for a long period of time, their mobile app did not validate any SSL/TLS server certificates, so anyone could man-in-the-middle communications between the app and Emirates servers. Since it is an app used by travellers, those who use it have a good chance of using it on MITM-prone third party networks at airports/hotels/cafes/etc. When they finally fixed it, they did that silently; users were not notified that their information may have been leaked/intercepted, and release notes didn't mention the security fixes. (More details on that issue here: http://huagati.blogspot.com/2017/03/dear-emirates-your-mobile-app-has.html )