[2022] quick golden pack question...

Just opened a golden pack and picked up my 5th copy of Vesuvan Duplimancy... I thought it should of been replaced with a card I didn't own from the set? If not protected then I should be opening my golden packs before I open my boosters...

Help me understand this after research on golden packs i came across this

"If you would receive a card but you have four copies of all cards of that rarity from that Standard-legal set, you will instead receive a card from another Standard-legal set. Only when you have four copies of all cards of that rarity from each set in Standard will cards be replaced by gems."

So what happened there?