I also am in agreement that Verduci was killed because of an existing feud between Figliomeni and Colluccio. The Italian article,although I find it to be well written & interesting, for the most part is basically a summary of what was said in other news sources or by book authors. Verduci association with Rizzuto would not be surprising considering the fact that Bruzzese had good relations with the Rizzuto's as did the Coluccio's with the Cun trera's. Their relations may have deteriorated while Vito was imprisoned for they saw an opportunity to expand.
In the article above Bruzzese is quoted as saying in 2009:
"Bruzzese can be heard exchanging gossip and complaints about upcoming weddings and telling Commisso about “disagreements” and messy infighting within various clans."
The infighting existed well before Verduci got killed.
This my take on it but I don't dispute that some of theories expressed by some of you to be also possible.