One can also point at an IP like the Simpsons being built at Universal even though it's Fox, either way it's another example of various theme park partnerships happening even if the park itself doesn't own the property.
And yeah, if I were Disney I'd be doing what I can to see about getting the rights for Bluey. It's an immensely popular show for very good reasons, it's big with merch and it has probably one of the broadest appeals for both kids and adults that I've seen from a preschool show.
Universal does it a ton to the point where Wall Street types wrote articles on if Universal (the studio) is in trouble because the theme parks seem to think they don't have enough big IPs to put in the parks. Universal has always been known to collaborate more, mostly because, up until Comcast came along, they didn't have much of a choice. But partnering has also proven to be a solid strategy not only in the theme park business, but building relationships that extend to other parts of the company (see: SNW rights -> The Super Mario Movie).
Think about the third party IPs Universal has today just at UOR: Potter - Hogsmeade, Diagon, Potter's London, Popeye, & Scooby-Doo (WB), Simpsons & Marvel (Disney), Spongebob, & MIB (Paramount), Transformers (Paramount/Mattel), Dr. Seuss (Sr. Seuss Enterprises), and Hello Kitty (Sanrio).
Historically: Jimmy Neutron, Ghostbusters (Paramount), Dudley Do-Right & Shrek (prior to buying Dreamworks), T2 (Disney), Curious George (Margaret & H.A. Rey estate?), Barney & Friends (Mattel), Nickeloden Studios (Viacom), The Art of Alfred Hitchcock (Based on Alfred Hitchcock's work - The Birds being the only Universal film),
Future: Potter - Ministry of Magic (WB), Mario, Donkey Kong & Zelda (Nintendo of America - Zelda not wholly owned).