I would say that they're already "taking it seriously" enough to consider any potential applications of blockchain technology in financial services.
It's important to distinguish between taking BTC seriously (most of them already are, even if they don't like the speculative nature of it and they would rather preserve fiat currency), and liking it.
fiat is getting extinct thats for sure
Pretty bold statement. IMO that's extremely unlikely because fiat currencies are something which banks have control over.
It's certainly not a reason for them to treat Bitcoin differently - if they were actually afraid of that happening, they would be
far more hostile towards Bitcoin than they are now. Compared to what they could be, I'd say they're fairly neutral right now.