A lot of people seem to miss the point of the Ea, they aren't nihilistic because of that one thing. It's the fact that they not only discovered the inevitable heat death of the universe, something they were entirely powerless to prevent, but the fact that they learned this not long after successfully discarding their physical bodies and becoming immortal. An achievement that was supposed to ensure that a scholarly race like the Ea could forever preserve their knowledge and accomplishments had succeeded in nothing but making themselves their own jailers to an apocalypse they hadn't foreseen. They'd essentially doomed themselves to be idle bystanders whilst everything they'd ever strove towards was rendered pointless, played out over thousands upon thousands of years. It's no surprise that this burden drove them kind of crazy and led to them trying to regain their mortal status so that they could die normally before this all came to pass.
Hmm yeah I guess that would make more sense, but it doesnt really fit with them thinking that informing our party (comprised of all mortals) what they learned was unimaginably cruel and would result in us also wanting to end it all.