I think it’s more the news article that’s upselling it and with it being “groundbreaking”, it is likely only at the initial stages.

Mice are usually the first phase are they do have a similar immune response (systemically), have a fast metabolism and quick to mature. They’re also clones, which helps eliminate external factors that could contribute to what they’re studying. More or less, mice are just a quicker litmus test to just show that something is possible and if it warrants a study on a closer analog.