Yes I understand that effect, and it makes sense that higher temperatures might cause more CO2 to come out of solution, as in a bottle of soda going flat more quickly at room temperature than in the refrigerator.
That said, I am not certain that the recent dramatic spike to 400 ppm of CO2 (from what I've read) could be entirely caused by the fairly moderate temperature rises measured in recent years.
Temperature change (blue) and carbon dioxide change (red)