For women with history of pregnancy loss, walking may aid chance of becoming pregnant. Results of a recent study to better understand modifiable factors such as physical activity that may affect a woman's ability to conceive a child suggest that walking may help women to improve their chances of becoming pregnant. Source 4h.
Walking has always been a proven method of exercise and also help a person feel better about themselves. To see that it can help with a loss is not really new news. I think everyone is different but on the same hand everyone can feel better by getting out and walking and interacting with others to help too.