The narrative behind your plan is "Rulers are so scared of the Goddesses that they force the people to build temples instead of getting food, causing the deaths of massive portions of the people, entire villages starving, causing the people to rise up and overthrow their oppressors." Or at least, that's my best understanding of your intent. I could be wrong, please tell me if I am.
I don't think losing about half our population (guess admittedly, based on the negative temp econ being about half our permanent econ), innovations (which are a confirmed thing that can be lost by having negative econ), and pissing off Arthryn even more as the leadership doesn't act in the best interests of the people, is the best plan to get rid of the monarchy. There is no way to know how the People will react, how the Monarchs will react to the famine, how the pantheon as a whole will react, or whether we'll get a bunch of aid sent to us from our vassals fixing the econ issue on its own, and keeping us from having any issues. We don't have enough info as to how the people will react to things to make this work. Especially with a goddess of propaganda on the side of the monarchy.