First, Trump rewards loyalty. 100 years ago during the 2024 Republican primaries, Trump was going through the sham trial and it was still unclear whether or not he was politically toast. Vivek was one of the few (if not the only) candidate who defended Trump in the debates, and later went on to be a prolific surrogate for him during the campaign. Vivek being incredibly wealthy from his pump-and-dump scheme probably gives him a few extra second chances in MAGA world, too.
Second, I think his H1-B comments are only disqualifying for the 4% of terminally online 20-30 year old MAGA guys who are redpilled on the JQ (jeet question). Most older people see him on Fox News occasionally and think "wow that articulate brown man sure does seem to know what he's talking about!" He'll have to have an answer prepared for the primary, but Vivek's talent is sounding confident and repackaging canned answers. Even if he hasn't changed his opinion, Vivek will dodge the question in a convincing enough way to satisfy most voters.