H1 Withdrawal necessary for consular application

Company A and Company B applies for H1B of a person residing in India and both the companies get approval for him. Now, this person chooses to join Company A. Is it necessary for Company B to withdraw his application?

Isn’t it automatically implied that this person will only work for Company A as he would be getting stamping from consulate only for Company A? OR is it necessary for Company B to withdraw?

Just forget about B and go with A. You should be fine. Obviously like you said when you get it stamped it will be for A.