Misha is describing how Robert Berens came to him about Cas's romantic confession to Dean. "Supernatural over the years made winks and nods to that potential relationship between Cas and Dean but it was never canon, it was innuendo" and he never thought the network would allow the show to openly acknowledge it. "Even back in 2020 it was still wow you can really do that?"
"The show was grounded in traditional macho male tropes"
So Misha is really proud of Cas's confession that the show could be inclusive.
"I love that Cas was not rejected in that moment"
Robert Berens was ready to move on SPN but stuck around in order to make sure Cas's arc could culminate in that romantic confession.
(I'm paraphrasing, some direct quotes)











