Someone I know who is on probation was arrested by his probation officer and the probation officer didnt read him his rights and also didnt tell him why he was being arrested
Criminal Defense Attorney
Law enforcement officers only have to read people their rights if they are going to question them while they are under arrest. Even if questioned without the benefit of miranda, the only effect is that the statement given by the arrestee cannot be used in court.
Although the better practice would be to tell people why they have been arrested, there's no rule requiring it at the time of arrest. The probation officer will have to file a probation warrant that outlines the charges.