I'm a former resident who just moved north to Salt Lake County, so please take that into consideration.
With that said, I'd like to voice my support for the adoption of these two mixed use zone categories.
Mixed use zoning allows for neighborhoods to be built with amenities (corner stores, office space, shops, etc.) closer to residential areas, thereby reducing the need for excess trips by car. This traffic reduction further increases safety around roadways and reduces pollution and carbon emissions.
Along with the other supporter, I want to emphasize that adopting these zoning categories does not imply using them all over Provo. It simply means having them ready to be used where appropriate. The city and neighborhood councils, as well as all residents, will still have the ability to ratify or deny any zone change proposal.
When I moved north for work (I hope to move back in a few years), I looked for a place similar to Provo's land use. It's proven difficult. Much of Utah is unfortunately too "separated" in use, in that large stretches of land are only residential, with no other use allowed by law. These zoning practices were created in the 1960's at a time when the car was seen as the way of the future, and there was a huge move away from mixed-use zoning. Now, society is beginning to aknowledge the inconveniences built into our environment by those decisions (i.e. traffic), as everyone is required by that design to drive for even the smallest errands. Mixed-use zoning represents a move towards healthier design that encourages walking for short trips by moving amenities closer to residents.
Even if Provo's zoning ordinances don't currently include "mixed-use" categories, the city of Provo is far more "mixed" in it's land use than most of Utah's towns and suburbs. nearly all historical development (predating the 60's) was "mixed-use", because euclidian zoning didn't exist yet. My recommendation for the residents of Provo is to value what you have and continue to encourage development in the direction of mixed-use zoning. This change to adopt the next categories seems like a simple, important step to me.