The Eagles album surpassed Thriller pretty recently. It seems like they surpassed Thriller in 2018. Edit: Here are some articles from 2018 when they surpassed Thriller: first, second, third.

Second, Eagles greatest hits is not the greatest selling album of all time. It only surpassed Thriller in the US. Thriller is still the best selling album of all time globally and by a huge margin. EDIT: Here is the RIAA charts. Here are the global numbers.

So the above comment is correct.