cant speak to the level of technical input Alfa brought with them, but the branding aspect of their involvement seemed the priority and coincided with a pretty big marketing push in N.America for the Giulia (including ads during the Super Bowl) and subsequent their launch of the Stelvio Quadrifoglio the 'worlds fastest' SUV wit F1 drivers doing their marketing duties.
just my perception but it always seemed more of a marketing effort capitalizing on that long past history...and with that history being brought to the forefront again i can see how that makes it seem more evocative then the Sauber name.
but for me, my immediate or personal history with the sport does not go back to the 40s/50s so what Alfa did never really resonated with me.
for myself, Sauber is a name that has been on the grid for the last 30 years. and while they may not have enjoyed top level success those Red Bull Saubers were iconic to me and now because RB has, on its own, achieved so much success, the tangible knowledge/history that i have takes me back to those early days with Sauber and thus making that Saber name much more evocative to me.
to each their own as always
, but for me i will lament the loss of the Sauber name far more than seeing the Alfa name leave the sport again.