Template:M summ 2002 ISDA 6(d)
This clause has nothing to do with grace periods and everything to do with Loss and Market Quotation (1992 ISDA) or Close-out Amounts (2002 ISDA) so expect to see it modified.
A popular parlour game amongst those pedants who still insist on using the 1992 ISDA[1] is to laboriously upgrade every inconsistent provision to the 2002 ISDA standard.
You might well ask why, but then you might well ask why anybody watches films from the Fast and Furious franchise. Because they can. Or, possibly, to preserve the slightly more generous grace periods for Failure to Pay[2] and Bankruptcy[3] (in which case, you’d retrofit longer grace periods into the new version, wouldn’t you? But no).