The little Chinese modules tend to have the most absolute bare-bones implementation that will work, not one compliant with manufacturer recommendations. (So they may not be as resilient or reliable as they could be.)
That IC happens to be a TI part, and TI is great about having EVMs (evaluation modules) for which they also provide the schematics, and reference designs (for products) that show the parts integrated as systems with other parts, for which they provide schematics and often PCB design files, etc. Take a look at the EVM for the part and do what it does, or if the part data sheet has a recommended PCB layout, follow it (as it will often have real-world values).
In the case of the DRV8833, the datasheet doesn't mention back EMF diodes, nor does the EMV schematic include them (and the EMVs tend to be balls-to-the-wall designs to let you push the component to its limits, so they include everything up to the kitchen sink), so I'd say it conclusively does not need them.