#3 Carrillo is extremely new to the main roster
In terms of main-roster tenure, Carrillo has the least amount of exposure on either Monday or Friday nights. That's perfectly fine, but stars so new to the roster usually have weeks of build-up matches or vignettes in order to introduce them to the WWE Universe. Aleister Black, despite wrestling on both shows for months, received this treatment following the Superstar Shakeup. He didn't have his first match as a member of the Blue brand until a few months later at Extreme Rules.
Carrillo literally joined RAW last month, yet will have already had a couple shots at a major title. He was drafted ahead of names like Buddy Murphy, Mustafa Ali, Erick Rowan, Samoa Joe, The Miz, King Corbin, Rey Mysterio, and Elias. Perhaps it was done as a shock pick, but all of the stars he was drafted before have had success or at least some crowd exposure in 2019.
Some of those stars are obviously on SmackDown, but the likes of Murphy, Mysterio, Rowan, and Joe are on RAW. Mysterio is busy with Brock Lesnar and Joe is injured. That's understandable, but Buddy Murphy was getting some great crowd reactions when he was involved with the Roman Reigns storyline in late spring and early summer. Rowan is a heel and is busy with his friend in the cage, so that's fine.
The point here is that there was little build or explanation for Carrillo receiving back-to-back-to-back shots at a mid-card title. Other stars who have built up at least a partial resume seem like they'd at least have more of a reason behind getting a shot at Styles.