Epic announced V-Bucks stranded on the macOS & iOS versions of Fortnite will be honored and credited to your account so can spend them on other platforms.
According to the leak, fortnite called the Monthly Crew Pack and it’ll give you a monthly allowance of V-Bucks, the new Battle Pass & skin when it releases.
Fortnite player who was playing on iOS up until Season 4 when the updates stopped coming, it sounds like Epic Games wants to reward you with some V-Bucks.