The character continues with a different performer
Netflix's season-four guide identifies Liam Hemsworth as Geralt of Rivia. The change follows Henry Cavill's portrayal in the first three seasons. Geralt remains the character at the center of the ongoing adaptation; a recast is different from replacing the whole series with a newly titled reboot.
The guide also identifies Laurence Fishburne as Regis and describes a fifth and final season filmed alongside the fourth. Those production details should be kept separate from guesses about why a performer left. The official cast record establishes who plays the role, not every private conversation behind a casting decision.
Source [1]Where this fits in the story
Netflix's cast introduction places Geralt, Yennefer and Ciri on separate paths after season three. That makes the season boundary useful context for returning viewers: the narrative follows earlier events even though Geralt's performer changes. This explainer does not disclose the season's ending or treat old casting news as a new departure. Readers comparing film and television recasting can use the related Superman guide to see how a separate continuity differs from an ongoing series.
Source [2]