Ranked Play Platinums facing Predators

The matchmaking system doesn't really care what rank you are or what rank you're facing. If there's not enough similarly skilled players in the matchmaker, it'll just take whoever is there and throw them into a match.

Example: Last season after not starting ranked for 2 weeks after it came out, my first ranked game was against Apex Predators after the matchmaker reported only having 57 people to start with. I got a Silver 5 and a Gold 2 player against a full champion premade of Apex Predators.