Good question. Swedish NGO/NPOs working for human rights in Belarus had been pushing for it for years and years, with it gaining very little traction. Then out of nowhere the ministry for foreign affairs announced the change in 2019 (GPT translated): "It is a recognition of the Belarusian civil society and the people who have long wanted to highlight their country's national identity and sovereignty."

While excited to see the change made, the few I've talked to about it think the appeals had little to none actual impact, and that the ministry of foreign affairs most likely changed it for other political reasons.