For those who were affected by this issue, you’ll be pleased to learn that Apple has since pushed out an update that has fixed the issue. Apple had actually attempted to fix this problem on the 3rd of May, but users were still reporting that after the update, the toggle remained greyed out. However, according to more recent reports, it appears that the latest update has fixed it.
With this problem being fixed, users now have the option of either globally turning tracking on or off. Before this, for those who were affected, they could only manage app tracking individually, which we guess is fine if you don’t have too many apps. However, the downside is that you have to remember to turn it on or off for each app, versus the global toggle that will disable tracking completely.
Note that preventing apps from tracking you doesn’t stop ads from being shown. Instead, since activity data can no longer be collected, the ads you see will be less targeted, if you have actually bothered to notice whether it did or not in the first place. In the meantime, it seems that so far, a study has found that 96% of iOS users have already opted out of tracking.