It's very unlikely to have been largely luck -> it's likely it wasn't mostly luck -> no reason to bring up luck as an argument. There's no fallacy here either,

It's very unlikely to have been largely luck -> it's likely it wasn't mostly luck -> no reason to bring up luck as an argument. There's no fallacy here either, the implication is he was repeatedly successful due to his business skills, not luck, which he can be reasonably expected to apply to his future ventures. To suggest otherwise would be falling for the old HN 'but technically' fallacy.