343 improves matchmaking and makes changes to Onyx and Champion CSR in February update.
If you've been getting frustrated with matchmaking in Halo 5: Guardians, you won't have to put up with it for much longer. In a community post today, 343 Industries noted that ranking had been affecting matchmakng search times for some players, leading them to "create alternate accounts or party up with people of much lower rank to find matches."
"We’ve implemented changes in our algorithm to get players at all skill levels even faster matches. This should improve matchmaking times and increase the number of people eligible to match for players at all skill levels as well as players in international regions."
Meanwhile, an exploit that allowed players to place into Champion simply by being amongst the first 200 people in Onyx to complete their placement matches in a season has also been addressed.
"We are doing two things to increase the competitiveness for Champions. First, the new minimum CSR to earn a Champion rank will be 1800 rather than 1500. Additionally, we’ve placed a cap on the highest CSR you can earn after your placement matches at 1700. These changes will make Champions a more elite group and reward players that prove they're amongst the top in the world."
These changes are being rolled out today for the February season through service side updates, so you don't even have to worry about downloading anything.