That doesn't matter. The same rules apply. You get a new voter ID card every two years that is not stamped with party affiliation until you vote in a party primary. If he has a voter ID already stamped, it is from a previous election cycle. When I worked as an election clerk, that ID would be valid for getting a ballot assuming of course that this person matched the age printed on the card and on the voting roll.
Yes, I got a new card in the mail recently too - what I’m referring to is requesting an absentee ballot - it is mailed to you so you have to state if you want the republican ballot or the dem one don’t you? They are different ballots.