The meta analysis is just looking at all the studies currently available and seeing if there is anything we can glean from them. I haven't looked in depth at the individual studies but they wouldn't be indicating that if you eat fewer than 5 meals/day that you won't burn fat at all in a calorie deficit. It seems that there was more fat burned while eating more meals based on the studies and based on the populations (sedentary, moderate/high carb diets). So obviously even if you ate fewer meals and were in a calorie deficit, you'd still lose fat but burns more fat? The studies may indicate that it is more frequent meals result in a greater amount of fat loss than less frequent meals.
As I said, it is whatever works best for you. I used to do 5-6 meals but I don't follow that anymore for my own reasons. Weight loss (aka fat loss) isn't always black and white with a lot of gray areas