Cannot find Memoji stickers on iPhone

1. In Messages, open a conversation or start a new conversation.
2. Tap the Plus button then tap More.
3. Tap the Stickers or More.. and Memoji

See the pic below

iOS updates aim to enhance user experience, boost security, and fix bugs rather than disrupt core features. Memoji Sticker issues after updates might stem from underlying, unmentioned factors. Updates won't typically alter personal data but may refine settings or features. Backup before major updates for safety. Review Apple's update details and backup advice for a smooth process.

Kindly consider checking your settings and addressing any device issues before attributing the issue to external factors. This could be a pure coincidence that the iOS update removed personal data.

Before initiating a standard iOS update, it's advisable to create a backup. Have you completed this step? If yes, proceed with the restoration from the backup.

See what each update does: About iOS 17 Updates, About iOS 16 Updates, About iOS 15 Updates, About iOS 14 Updates, About iOS 13 Updates, About iOS 12 Updates, and so on...