In all fairness to Josephine, she is the only senior age-eligible US woman* who was in the SB Top 75 apart from the 6, who all got 2 GPs, so I don't think it's unreasonable to award her one of the 2 host TBD spots - and I wouldn't have thought it unreasonable had they done so right from the off when the initial assignments came out. And she's not even the lowest-ranked host skater to get a GP assignment - she's SB69 while Yi Zhu is SB71.
*Thorngren, of course, was SB46 but we know she's moved on from skating at this time.