I'm not sure if this applies to all tickets or just Etihad Guest (reward programme) members.  It could be useful to some but I haven't checked into the details because I very much doubt it will be acceptable by the Thai authorities when applying for a Certificate of Entry.

 

COVID-19 global wellness insurance included on all bookings   Dear XXXXXX, we care about keeping you safe at every step of your journey. That’s why we’ve introduced COVID-19 global wellness insurance cover with every Etihad Airways ticket – just one of the ways we promise to keep you protected with Etihad Wellness. Choose from any of our 60 worldwide destinations and travel there with confidence knowing that you’ll be covered should you be diagnosed with COVID-19 whilst you’re away. We’ll take care of your medical expenses and quarantine costs. Book your flight with us today and you’ll be covered from the first day of your trip. Your cover will be valid worldwide for 31 days for travel until 31 December 2020.

Hum That would be great if they took care of the quarantine  bill, but surely there must be fine lines. 
Also only until December 2020.
For those who wish to leave Thailand and come back ...I guess they won't cover the expenses upon the arrival in the Kingdom... if the fly here

Worth noting though