Alfa Romeo’s design chief, Alessandro Maccolini, denies that the new Giulia was inspired by the BMW 3-series. Instead, he cites the 156 as the main reference.
I added the Jaguar XE for comparison. My own view is that this is a matter of convergent evolution while also feeling that the resemblance to the 156 is, at best, passing and perhaps coincidental. Those strakes on the Alfa’s bodyside are not very original but the idea is quite generic anyway.