It's not always meant that anyway. The title shot wasn't a thing for the first five Royal Rumbles, and then after that:
- Shawn Michaels won in 1995 and the main event of WrestleMania was Bam Bam Bigelow vs NFL's Lawrence Taylor.
- Austin won in 1997 and the main event was Undertaker vs Sid for the title, while Austin was involved in a No DQ match with Bret Hart (with Ken Shamrock as special referee).
- Vince won in 1999 and the main event was Austin vs The Rock for the title.
- Rey Mysterio win in 2006 and the main event was Cena vs Triple H.
- Undertaker won in 2007 and the main event was Cena vs Michaels.
- Cena won in 2008 and the main event was Undertaker vs Edge.
- Edge won in 2010 and the main event was Undertaker vs Michaels.
- Alberto Del Rio won in 2011 and the main event was Miz vs Cena.
- Sheamus won in 2012 and the main event was The Rock vs Cena.
- Orton won in 2017 and the main event was Reigns vs Undertaker.
- Nakamura won in 2018 and the main event was Lesnar vs Reigns.
Since the introduction of the women's Royal Rumble:
- Rollins won the men's match in 2019 but didn't main event (Becky Lynch as winner of the women's match did).
- Charlotte Flair won the women's match in 2020 but didn't main event either night (Undertaker vs AJ Styles was the other main event).
- Ronda Rousey won the women's match in 2022 but didn't main event either night (KO vs Austin was the other main event).
- Rhea Ripley won the women's match in 2023 but didn't main event either night (KO/Zayn vs The Usos was the other main event).
- Bayley won the women's match in 2024 but didn't main event either night (Rhodes/Rollins vs The Rock/Reigns was the other main event).