It's not a complete role reversal...
People are treating what happened at Sinsmas as a complete role reversal between Stolas and Blitz, where Blitz is going to be the one chasing after Stolas, and Stolas pushing his advances away...
When the situation is a bit more nuanced than that...
Blitz and Stolas both don't have their masks up
The reason why Stolas had such a hard time in the season was because he had to take down those impenetrable walls Blitz put around himself. In that same vein, Stolas also had these walls up when he communicated with Blitz as well.
By the end of the season finale, those walls are down and these gentlemen are able to speak to each other face to face without keeping up a facade.
Blitz and Stolas are together 24/7 now
The reason why it was difficult for them to communicate before was because they were operating under the terms of their transactional agreement where their only excuse to meeting each other was during the nights of the full moon.
However, by the end of the season, both characters live and work together.
Blitz and Stolas have wildly different problems they have to overcome
Blitz, before, was not in the right headspace to give or receive love because he was still under the belief that his love hurts people and that he didn't deserve to be loved. Remember, one botched love confession literally mutilated his best friend, killed his mom, and destroyed the lives of his entire circus family.
The reason why Stolas isn't in the right headspace to give or receive love is because he's still processing his new way of life as a commoner, and the fact that his daughter doesn't want to see him. If anything, the main obstacle keeping these bozos apart now is Octavia.
Blitz and Stolas do love each other
Despite all the bullshit these men have put each other through, they both do genuinely have feelings for each other. However, Blitz knows that what Stolas needs right now isn't his love, but his support. And Blitz is happy with that because the only thing he wants to do right now is be there for Stolas.
When Blitz lost everything in the circus fire, he was alone with nobody to help him and guide him. However, when Stolas lost everything during the trial, he wasn't alone because Blitz was there to pick him back up.
Blitz doesn't know how to give up
While it is true that Stolas shuts Blitz out at this moment, Blitz doesn't give up and use that as a sign of rejection.
Instead, Blitz improvises by inviting Stolas to dance, and Stolas reciprocates.
If Stolas didn't want to dance with Blitz, he didn't have to, he could have just as easily shooed him away but he didn't. In fact, Stolas looks so happy to be invited to dance.
Blitz has this knack for getting Stolas to laugh, even in his most darkest days... so that helps too.
This is Blitz's endgame, his goal. Blitz wants to be at a place where he and Stolas could be happy and healthy, and live a life with their daughters by their side. He wants this, and Blitz is going to operate in a way to achieve it.
Because that is who Blitz is...
He is a tenacious bastard that doesn't know how to give up. He wanted to be his own boss, so he opened a business. He wanted an easy way to get to earth, so he fucked a Prince. He wanted a family, so he made his own eclectic one.
Blitz, despite the fact that he can be a complete asshole and an idiot, usually has a way of getting what he wants in the end.