What if Ice Age ended after the third film?

Almost everyone agrees that Fox keeps making more Ice Age movies, but what if the series was a trilogy without more movies being announced, leading Blue Sky Studios to make more movies based on original ideas?

This theory is interconnected to What if Comcast acquired The Walt Disney Company back in 2004?, meaning that Disney didn't acquire Fox in this reality.

Changes

 * Dawn of the Dinosaurs would serve as the series finale. However:
 * A Mammoth Christmas still exists, but not The Great Egg-Scapade.
 * Video games based on the franchise would still be developed, although with several changes to only include contents from the first three films.
 * Continental Drift, Collision Course and The Ice Age Adventures of Buck Wild would never exist due to being made as cash grabs, being replaced with other projects.
 * The shorts featuring Scrat would still be continued as long as they are original rather than teasers/sneak peeks for next sequels.
 * Also, Scrat would still be the mascot of Blue Sky Studios.
 * Rio 2 gets tweaked to tell a new plot.
 * Blue Sky Studios would have never closed down.
 * The studio would release at least a film by year and occasionally two.
 * Most of the cancelled projects would be produced.
 * Spies in Disguise would perform much better at the box office.

Films

 * 1) Ice Age (2002)
 * 2) Robots (2005)
 * 3) Ice Age: The Meltdown (2006)
 * 4) Horton Hears a Who! (2008)
 * 5) Ice Age: Dawn of the Dinosaurs (2009)
 * 6) /Spore/ (2010)
 * 7) Rio (2011)
 * 8) /The Iguana Brothers/ (2012)
 * 9) Epic (2013)
 * 10) /Rio 2/ (2014)
 * 11) /The Wainscott Weasel/ (2015)
 * 12) The Peanuts Movie (2015)
 * 13) /Mutts/ (2016)
 * 14) /Left Tern/ (2017)
 * 15) Ferdinand (2017)
 * 16) /Anubis/ (2018)
 * 17) /Foster/ (2019)
 * 18) Spies in Disguise (2019)
 * 19) /The Forresters/ (2020)
 * 20) /Santa Calls/ (2020)
 * 21) /Mystery: Check!/ (2021)
 * 22) /Nimona/ (2022)
 * 23) /Olive the Other Reindeer/ (2022)
 * 24) /The Magic Finger/ (2023)
 * 25) /Watership Down/ (2024)
 * 26) [original film] (2024)

In development

 * King of the Jungle
 * The Cyclone Thunderstorm!
 * The Blackouts
 * Frogkisser!