They can call it Toto if they want, fans can decide if they want to buy a ticket. People want to get in a room (someday) and listen to that music. No one is left in the original Wolfgang Amedeus Mozart band but people still go to their concerts anyway. David Paich is apparently in poor health and can't tour anymore. I ran into Bobby Kimball at NAMM once and when they got back together he apparently didn't realise he was in Steve's Band. He gave me an intense look and with heavy beer breath said, "No one tells BC what to do!" OK dude good luck with the BC Band playing the Indian casino outside Bakersfield or whatever.
There was a Sting documentary in the 80s, about the original solo lineup, "Bring On The Night." Miles Copeland was the band manager, and he was getting some pushback from the band that they were getting paid so much less than Sting. He said something like, "if we announce you're not going to make the concert, how many people are going to ask for a refund? 6, 7 people. If we announce that Sting isn't going to make it, how many people will ask for a refund? Every single one of them!"