回複：Help! PJiang & Xiaobaotu

I think it does not matter provided he returns before his re-entry expires. His re-entry won't be renewed at the border in any case, and the new I-94 will always replace the old one, which is going to be 3 years, sooner or later. However if he has the new visa he can stay beyond the date his re-entry expires but he has to apply for a re-entry. In this case he may receive multiple entries again.

Good luck!