REF: maybe_promote refactor/cleanup (#28897)
REF: maybe_promote refactor/cleanup (#28897)


jorisvandenbossche/pandas,gfyoung/pandas,pandas-dev/pandas,gfyoung/pandas,dsm054/pandas,datapythonista/pandas,TomAugspurger/pandas,dsm054/pandas,pandas-dev/pandas,datapythonista/pandas,dsm054/pandas,datapythonista/pandas,gfyoung/pandas,jreback/pandas,rs2/pandas,TomAugspurger/pandas,TomAugspurger/pandas,jorisvandenbossche/pandas,jorisvandenbossche/pandas,gfyoung/pandas,datapythonista/pandas,jreback/pandas,jorisvandenbossche/pandas,dsm054/pandas,TomAugspurger/pandas,pandas-dev/pandas,jreback/pandas,rs2/pandas,jreback/pandas,rs2/pandas,pandas-dev/pandas,dsm054/pandas,rs2/pandas,jreback/pandas,gfyoung/pandas