That's assuming hashing power will determine the outcome.
In the exchanges runs will take place. The actual economic users will vote this issue out.
In the end spreadsheets will be updated, and miners won't want to spend their electricity on a chain that went unprofitable.
Miners may have the software coming from segwit2x, and be the ones who actually provide the technical consensus. But the economic consensus will trump everything else; and late software along with questionable roadmap does not inspire confidence.