if the rumour turns out to be true (and I think unless Intel picks up and invent something amazing - unlikely) then you want to get the last intel from Apple as that will bridge the period for you. Because if its going to be something like PowerPC to Intel (different scenario to this one though) then there will be lot of developers behind as it takes time to recode the apps to new architecture and also, some developers will simply not do it. Sure, we will probably get a simulator but it won't be ideal. Thats why I think its good to get 2019 machine (or 2020 if there is one) and keep it for about 4-5 years. That would give around 3 years after the 'switch' and by then most apps will be out recoded.