I don’t believe you’ve seen that 16 week thing on this site, at least not recently. UW moved to 12 weeks for greatest accuracy years ago. Maybe you aren’t talking about the blot in that statement.
The IgG test misses 30% of HSV 1 and 8% of HSV 2 compared to the blot.
If that statistic is what concerns you, you could do the western blot for greater certainty.
Terri