My experience was a little different. The Hornady Creedmoor brass I had sucked. The primer pockets opened up after 4x firings. The Lapua brass I’ve been using is now at 17x firing and is showing no signs of slowing down.
Not a sign of that on my HRN 6.5CM brass.
I have a bunch of Lapua in .223, .308, and 6.5CM waiting while I continue to use my original .223 PRVI/PPU, Hornady 6.5CM, and PRVI/PPU .308. I have purchased 4 to 5 boxes of each in Lapua on various sales, under the erroneous impression that the brass I was currently using NFG and was going to fall apart after 3, or 4 or, 'you might actually get 5 reloads out of it' type crap on here and other reloading/shooting forums. Most of my PRVI .223 brass is up into the high teens to very low twenties of reloads. I finally had to cull one set of 50 due to a neck split during neck bushing resizing. That particular reload was at 23x and I dumped that entire 50. The rest are still working just fine at this point. My PRVI .308 brass is hanging in, in the low to mid teens of reloads. Unfortunately I was reloading for two different rifles for a while and taking it back to SAAMI minimums with full length resizing on some of it. I think that stuff is probably dodgy due to excess body stretching and possible body thinning just above the web, and I am considering junking it. Fortunately I put one of the two .308's into semi-retirement but the other hasn't seen a lot of use for a while either as I have been out shooting the 6.5CM instead. The Hornady 6.5 brass is in the high singles to very low teens for number of reloads as I mentioned previously. My PRVI 300WM is in the high singles to very low teens as well and I have never used anything other than this in that rifle.
My take on it all is now, hmm, sounds possible but unless it makes sense and I see signs of it for myself . . .
As well, I think that some people treat brass they think is crappy, well, like crap, and if it doesn't work out, well it was just junk to begin with so . . .
And one final observation/note is that Lapua 6.5CM is SR pocket so if you are running hot loads it can withstand the higher pressures better.
Depending on the bullet, and range, I run my reloads at medium going up to pretty warm on the lighter bullets just to see where they work. I have just been testing the Hornady 147gr ELD-M and so far it has been spectacular with H4350 at around 2630fps, at least out to 500m. My next loading will be going up and finding out what it can on it way towards 2850+ fps. I don't expect to get that far but I'll let the ammo tell me where to quit.