After looking at various news sites and a statement from Oprah Winfrey herself, I think that this claimed can be deemed as false.
According to Newsweek, a TikTok video that was originally posted by AlltheNope made numerous allegations, which stated that Winfrey hired a private firefighting team before the fires spread, private security to prevent people from seeking shelter at her property, and bought her land for "pennies on the dollar."
However, none of the claims in the TikTok were backed with evidence, and Newsweek was unable to determine the truth of this information/data anywhere. Winfrey has faced criticism before (during the wildfire crisis), as well as other news articles using falsified photos against her.
Furthermore, Poynter states that the accusation of hiring a private firefighting team comes after Winfrey and Dwayne Johnson established the "People's Fund of Maui." A comment was made in an Instagram video by a woman claiming that Winfrey hired the firefighting team secretly to protect her own home, but Meta flagged the post to combat false news.
Poynter did not find any government records or news reports that Winfrey hired a private team to protect her properties. No concrete evidence is provided to back this claim.