I don't know what you are talking about. The plan seems to be somewhat vague.
First, if there were consensus to agree to seg wit then some of the witholders from signaling segwit could start signaling seg wit.. but they wont agree to signal seg wit without a 2mb increase first and in the form of a hardfork... so? What does that mean?
It means that the supposed supporters of a compromise do not agree to signal seg wit unless they get a 2 mb increase in the form of a hard fork. A hardfork is not going to fly because it is not necessary.
seg wit has already been vetted and approved but a 2mb increase has not.. so that would need to be coded and tested... Anyone did that yet?
So, how can core just agree? You want them to agree to a hardfork? You said that no change in governance.. ? Looks like the threshold is 80% rather than 95%, and that appears to be a change in governance, no? change from 95% to 80%, right? that is a change?
Vague is good at this juncture because if it is going be something that consensus is built around core will need to put their stamp on it and ultimately write the code.
It is not currently possible to build consensus for SegWit by itself without an increase in block size. That leaves us with three choices.
1) Stagnation forever in the current state with no change ever.
2) Contentious hardfork with a split into two separate coins.
3) Some compromise position that is safe and that all parties can live with.
Of these three I believe option number 3 to be superior. Therefore what I hope to see happen is bitcoin core testing and vetting a combination package of 2mb hardfork + SegWit with whatever safeguards and testing they feel is necessary to avoid problems.
I believe it
may be possible to build a broad consensus around this option that all parties can live with.