Apple didn't remove it. It's not something Apple would selectively remove. It's certainly still on my iPhone 12 and 12 Pro Max. But it's possible something happened in the update on your phone.
When you do an iOS update, it is advisable to Force Restart your phone immediately after downloading the update. Did you do that? If not and your signature is correct and you have an iPhone 11 do the following:
- Press and quickly release the volume up button
- Then press and quickly release the volume down button
- Then press and KEEP HOLDING the side power button (keep holding past the swipe to power off) until you see the Apple Logo, then let go
See if the emergency alert options appear at the bottom of Settings > Notifications