I would say that's too much. There is not really a "non-Food" Growth in the 4x games, and I don't think people will confuse Gold to other things, unlike Science. Faith and Ethics are totally different ideas/concepts, the same goes for Favor and Prestige as well. My suggestion of "Science to Knowledge" is to avoid confusion, instead of (unnecessary) abstraction.
I think there could be a place for a 'non-Food' Growth mechanic in 4X Historical games, though. Admittedly, Food was primary in early cities, and there is strong evidence that many Neolithic and Bronze/Chacolithic Era cities were abandoned when climate/terrain changes cut into the food supply - people reverted back to hunter-gatherer or pastoral lifestyles and took off. Later, that simply wasn't an option.
More importantly, population growth in cities for most of history was not due to having enough food to sustain birth rates: birth rates and child survival rates in cities were generally abysmal, because the crowded urban conditions from the beginning were near-perfect conditions for plague and disease in general. All the cities until the sanitation discoveries of the Industrial Era were dependent on migration from the country to maintain and increase their population.
That means perhaps Food would be simply a limitation of growth - not enough food, no growth at all - but actual increase would come from factors that Attract migrants. Those would be primarily two things: better lifestyle in jobs that produce more 'income' however that is measured, and better access to Good Things ranging from Entertainment, Religion, Power, Prestige, Exotic Goods/Markets, etc. The actual in-game mechanic could be the number of Job-Producing Buildings in the city (Markets, Workshops, Factories, Harbor Facilities, etc) and the number of Good Thing Producing Buildings (Temple, Palace, Arena, Amphitheater, etc) the combined total giving a number of 'jobs' to be filled, the higher the more 'pull' on country folk to move in.
This would also allow the simulation of some of the massive growth seen episodically throughout history, as, for instance Colonial Cities frequently exploded when they appeared to offer high paying or at least high opportunity jobs not available 'back home' or Gold Rushes and Silver Strikes brought people in a rush - like in California/San Francisco in 1849, or the Joachimthal silver strike of the late Middle Ages.