You are allowed to Cancellation the date and/or time of your Etihad Airlines flight free of charge:

Your flight falls under the COVID-19 travel exemption, ie:
Your itinerary includes flights to/from/via airport on Etihad Airlines and
Your ticket was issued on/before June 10, 2022 with a travel date between March 26, 2022 and May 31, 2022

Your flight from the U.S.A., Mexico, Peru and Brazil:

More than 31 minutes late, or
Departs 16 minutes earlier
Your flight has been canceled and the alternative flight offered to you is not suitable for you.
The fare rules of your ticket allow you to Cancellation your flight (with or without a fee).
If you or an accompanying passenger becomes ill or injured and you provide a valid medical certificate from a qualified medical professional, this will prevent you from catching your flight.
Your co-passenger or immediate family member dies by submitting the death certificate.

Note. You can Cancellation your flight route as long as you pay the applicable difference in fares, taxes etc.

Etihad Airways Cancellation Flight Policy
Online If you purchased your ticket online from the Etihad Airlines website

You purchased your ticket from Etihad Airlines through a travel agent Etihad airways flight Cancellation policy for involuntary Cancellations due to reasons beyond Etihad Airlines' control
Involuntary schedule Cancellations refer to flight Cancellations made by Etihad Airlines for reasons beyond its control—bad weather, traffic conditions, etc.—or for reasons within its control—maintenance problems, equipment malfunctions, etc.
There are also unintended schedule Cancellations for the United States, Mexico, Peru and Brazil:

A flight delay of more than 31 minutes
The flight took off before 16 minutes
Flight Cancellation by another airline due to cancellation, delay or other reasons beyond the passenger's control

If your flight undergoes an involuntary schedule Cancellation due to any of the above reasons, you have 2 options:

Rebook at no extra cost on the next available Etihad Airlines Group flight. Etihad Airlines Group aircraft include Etihad Airlines and Air Etihad Airlines operating flights on international routes and codeshare flights operated by Etihad Airlines, Etihad Airlines Wings and IBX Airlines, AIR DO, Solaceed Air, Air Oriental Air Bridge and Star Flyer. On domestic routes on Etihad Airlines.