Yep, that's correct. At 2GHz you can get away with just about as much pin recession as you want, as long as you don't have protrusion. You're also correct to note that the low-end cables are quite shocking in this regard. You'll find protrusion, you'll find recession so severe that the tip of the pin is barely visible, you'll find intermittent shorts from big solder blobs at the center-conductor/pin interface that aren't mechanically secured or otherwise prevented from contacting the outer shell, you'll find outer conductor mesh so scant that wifi packets will get into a terminated cable like it was an antenna, you'll find center pins that erupt into a full coat of green copper oxide even though the coupling nut still looks shiny and golden -- it's really the wild west out there in the world of cheap cables.