a fork is a different path.
it does not mean it has to survive more than on block. it does not mean it has to live on forever. it just means a different path has opened up
orphans are where forks are killed
Yes. I assumed that a softfork was named as such not because of a literal chain split,
but because its effect was likened to a chain split in that it allowed protocol changes.
For example, if you could make certain aspects more "strict" within the preexisting
protocol, in my mind, you wouldn't need to create a new chain to enforce this, but a
"layer" within the chain.
So back to the OP, I should have stated this:
SegWit would only be an "altcoin" if there was
a hardfork with two surviving chains.
Altcoins, in the OPs intention, are only created by
hardforks. Softforks can't make altcoins two surviving chains.
If SegWit survives and the minority chain dies off, SegWit transforms from altcoin into "Bitcoin".If BU survives and the minority chain dies off, BU transforms from altcoin into "Bitcoin".The only time a "protocol change" skips altcoins status entirely, is with very high consensus. Very high consensus can't make two surviving chains.