"Fitzgerald grew up in a blue-collar family on Chicago’s South Side, played at Northwestern as an undersized linebacker on their last Big Ten title team (1996) and has resisted endless overtures over the years to leave. (That includes calls from six different NFL teams and interest from USC, Michigan and Penn State. Fitzgerald never spoke directly to any of them.) When the steel finally went into the ground, he admits he got “really emotional.” And when Northwestern held its first practice on April 7, he says “it just smacked me in the face.” As his team went through drills, Fitzgerald looked around and became so overwhelmed he began to cry. (Phillips and Ryan both did as well on Ryan’s first tour of the near-completed facility.)"
https://sports.yahoo.com/move-clems...-unparalleled-college-football-220858185.html
Notre Dame also showed interest.
Also of note:
"Fitzgerald ended up signing a 10-year contract soon after. (He’s since done another.) Included in it were deadlines that would waive his buyout if the facility wasn’t finished, a common contractual nuance when schools promise new facilities. Ryan, 81, has been around long enough to recall Parseghian leaving for Notre Dame and Gary Barnett for Colorado. He didn’t want to lose another top-shelf coach, calling the day Fitzgerald decided to stay, “a historical moment in time for the university. Not just the athletic program, but the university in total.”
So yes, the facilities were built in part to keep Fitz around.
You didn’t list the most compelling paragraph in that article which proves there is a direct link between Fitzgerald considering another job and this facility being built. The one which describes how Ryan and Osborne scrambled back to Chicago in January 2011 to discuss what it would take to prevent Fitzgerald from meeting with Michigan. The seeds for this new facility were planted at that meeting. If that does not prove a definitive link, I don’t know what does.