It will have to be enabled manually.
After migrating to iOS 12.2 iPhone and iPad users will be missing one of the features of the Safari browser, which will be off by default. Apple officially announced that iOS 12.2 default is disabled, which is responsible for browser access to the gyroscope and accelerometer of mobile devices. Apple will disable the feature because of security reasons, but users will have the option to enable it if desired.
In all current versions of iOS 12 Safari provided free access to gyroscope and accelerometer. Due to this, the iPhone and iPad users can browse from their devices and various online websites, objects which move and rotate after the device.
For example, the company Apple has such a page available at this link. If you switch to it from an iPhone or iPad, it will be “to twist in hands” 6.5-inch iPhone XS Max. This can be useful before buying.
In 12.2 iOS the Safari browser will be disabled access gyro and accelerometer, at least by default. Apple will do this due to the fact that the Internet began to appear the spy websites track iPhone and iPad users, receiving data from the device sensors.
However, users will have the possibility to activate access Safari to sensors if desired. This can be done in the browser settings, which will be a new switch.
The final version of iOS 12.2 are expected in February-March 2019. Most likely, Apple will release an update after finishing his March presentation, which will be presented to 2019 iPad, iPad mini 5 , and other novelties.