if vito were alive, then there would be no point to betray michael
if vito were just an advisor, but still alive, michael would have waited until vito was dead, just like he waited until their mother was dead before murdering fredo
if vito was a holographic chatbot, then vito is going to tell michael how great he is and help him register his patent and become a billionaire from being an inventor and legitimate businessman with an ai consigliere.
okay, that aside, if it were me, i'd be like vito and never put myself in that situation. you would keep fredo close and resist temptation to expand through extreme human exploitation. fredo was a moron and in the wild he would be dangerous to the family.
in reality, powerful families either castrate them and put them out to pasture or cull people like fredo.
examples would be Michael Rockefeller and Amschel Mayor James Rothschild. Michael was put out to pasture and Amschel was killed.

Or like if Michael had some greaseball version of Superman's Fortress of Solitude, with breadsticks instead of crystals, where he could still talk to Marlon Brando's hologram or whatever, what would he have to say about it

yeah, i get that
if vito were alive he would have had to go along with whatever michael wanted
you don't go against family and michael is the head of the family
fredo went against michael, so michael had to deal with it

For going against Michael as he did in the film.

trick question since he never would have gone against Vito.

Banished him to the underland, eh

Sent him to live in the old Country. Maybe Sardinia or Tuscany
The only poster who had his account banned 4 times without ever breaking any rules each of those times.