Ranked Play Platinums facing Predators

I would guess the matchmaking system is matching players according to a normal curved distribution around the matchs average MMR that gradually expands its deviation parameters if there are too few players to fill up a lobby. So if the average MMR for your match is lets say, Platinum1, the matchmaking system will start to search for "most" players around Platinum1,  "a little less" players maybe around Platinum2 and Diamond4, and " very few" players in Platinum3 and Diamond3. But if it cant find players with this narrow deviation, it might broaden it so it has  "most" players from Plat2 to Diamond 1,  "a little less" players around Plat4 to Diamond3 , and " very few" players all the way from Gold to Predator.

A friend of mine has worked in the gaming industry since 2006 and according to him, this is a common basic principle to design a MMR based matching making, but can ofc not be sure how Apex algorithm works. I guess sometimes you get unlucky and get picked to a match where the average is above your MMR, and sometimes you get lucky when the average MMR is below your MMR.