Considering the article notes she wasn't going to see much playing time, the redshirt also lets her retain her full eligibility versus losing it.
I like the approach as it gives her a chance to develop and be ready to prover herself next season. Personally, I would have liked to have seen Bostock do this instead of enrolling early in 2022-2023. Joining the team midway felt like she was short-changing herself.
Sometimes I wonder why programs don't do this more often. Is it a cost factor? No idea but it's something that I wonder about on occasion.