^ I don't know what 'pattern' you're seeing, but what you're saying makes no sense.
Okay. I shall restate in a more tl'dr friendly manner:
Pattern: Flarrow always repeatedly awkwardly mentions its crossovers.
Pattern break: Then for the biggest crossover ever, they suddenly decide not to even acknowledge one happened. Ever.
Hope: Maybe they didn't mention it because they couldn't figure out how traveling to a new Earth could be relevant to the plot?
Pattern: Flarrow is silent on all things Superman.
Pattern Break: Supergirl casts Superman.
Pattern consistency: Flarrow is silent on all things Supergirl.
Hope: Maybe they didn't ever mention it because they just never had time.
Pattern: WB movies puts embargoes on CW TV.
Pattern Break: WB does not put embargoes on Supergirl.
Hope: Maybe WB puts embargoes on Supergirl too, and we just don't know about it.
Hope is a beautiful thing. But it's not evidence, and it doesn't make 'sense.' That's why it's hope.