Looking into the hire a little more...I found the last few lines of this article interesting. As the hire was made by a similarly "lame duck" GM who turned to a "familiar face" as manager as I suspect Minasian will do in recommending/hiring Showalter...
As for Melvin, he’ll now take over another team in need of a culture change. After winning 107 games in 2021, the Giants are 159-163 over the last two seasons, and Kapler’s hands-off managerial style was starting to seem more like a detriment than a plus. Several Giants players, either on or off the record, felt the club was somewhat directionless, with Logan Webb outright stating he felt “we have to make some big changes in here to create that winning culture.”
These criticisms extended not only to Kapler but to president of baseball operations Farhan Zaidi, whose contract is believed to run only through the end of the 2024 season. As such, Zaidi is also certainly feeling the pressure to build a contending roster, and the Giants are expected to be aggressive shoppers this winter after missing out on both Aaron Judge and Carlos Correa as a big-ticket addition last offseason. Faced with what might be a make-or-break scenario, it probably isn’t surprising that Zaidi has turned to a familiar face as manager — Zaidi previously worked as the Athletics’ assistant GM during Melvin’s tenure in Oakland.
https://www.mlbtraderumors.com/2023/10/giants-to-hire-bob-melvin-as-manager.html