When ios 17 for iPhone X comes

It won't. An iPhone 8, iPhone 8 Plus, or iPhone X isn't capable of 17 or above; they require an A12 or better CPU.

(254596)

Unfortunately, iOS 17 is not supported on the iPhone X. With an iPhone, you receive the latest iOS updates up to 5 years after the release of the device, so your model has aged out.

For more information: iPhone models compatible with iOS 17 – Apple Support (MY)