I'm not a Deborah/Ava
for a few reasons
Jean Smart is over 40 years older than Hannah Einbinder. I'm no age gap police and yes Jean Smart could probably pass for 40s/50s but that age gap is quite something. To put it in perspective, Jean Smart had completed her entire run on Designing Women years before Einbinder was even born.
While Ava and Hannah share a rare intimacy with each other, I interpret the relationship as mentorship, friendship, and professionals. Sure, I can agree that they are prioritizing each other ahead of romances, but I don't think that means they belong together.
One could argue that Ava has a latent crush on Deborah. Maybe!! She had the sex dream. But I think the sex dream was a literalization of this meaningful relationship where she is allowed to grow, develop professionally, and find some authentic self worth. Ava and Deborah are quite alike, and I feel like the dream Deborah was a projection of something within her subconscious (like in the movie Inception)
Deborah is straight. She says so on the cruise ship. Unless the show wants us to think this woman has no awareness of her self, we have to take her at her word.
Personally I feel like any kind of romantic development would ruin this very unique relationship and would make it far less interesting