Given the younger age, this storyline could always be activated if needed if they do bring Migs back. Given the 10-year time difference, it's not difficult to explain away that the sharpshooter was a younger Migs (thus justifying the different actor). It's not like it's not done before. The way they did it actually leaves them flexibility. To be sure, it'd be an Easter egg. It develops Migs' story more than Andor's.

It's not about whether Sam deserves better. It is about the story. The story is such that in the MCU, Sam no longer has a backer in power. Valentina is the one who wields the influence in America in the MCU. The story is also that there isn't even a confirmed roster of Avengers, just different heroes working together, like Carol, Bruce & Wong (with Shang Chi & AMerica Chavez)

Because the hype fizzled. It was as much Majors' conviction as the poor reception of Quantumania. In my view, that movie ruined Kang. It is a character with much potential, but it needed another writer.