I guess I will have to withhold judgement until more information is available.
It would have made a lot of sense to add an economy plus section at the same time as reconfiguring the 738 and 739s with new seats and power. While I'm sure it could be done, it certainly seems very inefficient to go back and remove a row of seats a few months after adding a row of seats. So, I would be surprised if this is the route they are taking.
My concern would be if they just preserve the "NEW" configuration and then designate the exit rows and bulkhead as premium seating. OR, worse, if they decide to expand legroom in a few rows at the expense of legroom in the remaining rows (which is basically what Delta has done on their newer 737 NGs).
Personally, I would rather have 31-32" pitch in most of economy, which Alaska currently has, rather than less legroom in most of the cabin and just a few rows with more legroom.