Most players at that time had Gonzales' serve motion. I'm not sure why the focus on comparison against Gonzales' specifically.
Back in those days, you were far more restricted by the following two things:
1) Rules about foot placement
2) Technology - heaver racquets and very limited string differences and configurations
Laver's serve was the quintessential evolution towards a pinpoint serve heavily engaging an extreme SSC, extreme racquet drop, and strong kinetic chain.