If you look at bands from the 1950's. Some of them are touring with no original members at all. It's because most of the original members are either dead or buried.

Rock bands are a buisness. Where there is money to be made, someone will figure out a way to make it. If Neal Schon, and Jon Cain died tomorrow, do you think that Ross Valory wouldn't take the name Journey and still tour with it. It doesn't matter that he is just a bass player that had very little to do with anything other than keeping the bass lines. He has even less of a role in the sound of Journey than Gregg Rolie did! LOL

To make a long story short, if there is a market for the music, someone will be on tour with it...