I saw possibility romantically but quickly realized it's just another friendship ship. Nothing to get excited about yeah she had for like 1 day childhood hero crush but it seemed over with rather quickly.
I'm not sure about that. The sub-plot of Serena knowing Ash from Childhood and having a canonical crush is not going to be quickly resolve considering how other subplots from the anime are handled in the past, like the Buziel and Aipom Trade, Chimchar joining Ash, Misty denying that she has a crush on Ash, and so forth. Given how the marketing team are giving ship teases left to right, such implying Serena's jealousy in the Sylveon episode and the Pokévison episode, I expect that sub-plot to resurface in the future.
Well obviously, but it might end up phasing out towards the end of the saga. Knowing the cycle of the show and how Serena won't have any relevance after XY, it makes me wonder where it can go before the gen ends.