The Segwit theft would require a hard fork.
And if you are going to have a successful theft by hard fork, you may as well steal from the legacy addresses as well.
This is just more Bcash lol bullshit.
The chain committing the "theft" could not be considered a hard or a soft fork since it it would be implemented by a miner running a node with an older version of Bitcoin. The older software will simply be following the same old rules that it understands. In order to be considered a fork, rules need to be changed. In this case, if the chain were to truly split because all the nodes could not reach an agreement, the chain that would be considered "forking off" would be the chain following the Segwit chain. After all, Segwit is considered a "soft fork." Please note that I am not convinced that both these chains could survive for long, simutaneously. Either one or the other is going to be orphaned off.
I thought that we already did some variation of this in August 2017? There were various decisions to move forward with segwit that involved threats to get left behind and required at least 95% to follow.. then the new rule set was locked in. If there is a desire to go back to some old rules, then there is a need for more than 51%.. and more likely to be something like 95%, but of course the consensus rules could be changed. Alternatively, if there is a suspected threat, then could there be rule sets that address the threat?
I recall some kind of BIP that went into place that pretty much kicked some nodes off the network if they were running certain kinds of attack software.. wasn't it the nodes that signalling support for segwit2x or some other behavior that was no longer be allowed, and had like a 1 year period before it would become strictly implemented?
I think part of my point is that if there certain suspected security problems, such as deviant minority nodes (miners) then there could be ways for the network to discontinue to recognize them by rules that are agreed to by the vast majority. and even if that is not a hardfork, exactly, the effects are nearly the same as a hardfork.