I would say it depends on the manner of a seventh place finish next season.
If we are still miles ahead of the eighth placed team and acquit ourselves well in one or both of the domestic cups plus progress deep into the Europa League then, all things being equal, there would be no case for sacking Ronald given the scenario you have outlined.
That would all amount to an upward trajectory even if there is no improvement in league position.
However, if we are involved in a dogfight for seventh with say, Stoke, Baggies or Barcodes and clinch it on the last day by a very narrow margin with a much reduced points tally from this season plus make absolutely no show in the domestic cups again and fail to make it out the EL group stage then it would have to be viewed as a regression from what has been a much improved campaign.
In that case I think questions would need to be asked about what progress we are making overall under him....though at that stage I would say, like Martinez, his first season buys him a third season even the second is pretty disappointing.
But.
That ain't going to happen
I still fancy we will pip Arsenal and finish sixth this season.
And I think next season will see us come on leaps and bounds