M852 match, with the knurled marks, first came out in 1980. As noted in the previous thread, it was to ID the not for combat 168 gr HPBT bullet. Incidentally, it is the Hague Convention, not the Geneva, that prohibits hollow point ammo.
As to weakening it, like most things in the gun world, that's a point of debate.
Depends on what you're loading it for. If you fireform for your bolt gun and neck size only it's not going to have much if any effect. If you're full length sizing and setting the shoulder way back on a brass eating M1A, that knurling is right where case separation is likely to happen anyway so it isn't helping. Personally, I use it in a bolt action like any other brass but I'd stop after three loads in a semi.
Here's a good article on the history of National Match ammo:
http://riflemansjournal.blogspot.com...1_archive.html