Artistic License – Sports: It looks like Burns relocates the Celtics to Springfield in the middle of the season so he doesn't have to constantly travel to Austin. In real life, Burns would have to move the team after the season ended. Only in an emergency could a team move to a different city during the season, such as when Hurricane Katrina forced the New Orleans Saints to play their home games for the 2005 season at LSU's football stadium in Baton Rouge, and the Alamodome in San Antonio (their first home game, against the New York Giants, had to be moved to Giants Stadium in New Jersey on short notice). The city's NBA team, the New Orleans Hornets, had to spend two seasons in Oklahoma City, even calling themselves the New Orleans/Oklahoma City Hornets. The hurricane, though, took place before NBA training camp, meaning the Hornets' temporary relocation still took place before the season actually started, whereas the NFL preseason was reaching its end when the storm struck.
The Cameo: Amazon.com founder and CEO Jeff Bezos and sportscaster Marv Albert.
Disco Dan: Mr. Burns attempts to sing the national anthem at the Excitement's first home game in the new arena. According to him, the lyrics are, "My country, 'tis of thee/Austria-Hungary, obey your king". Smithers interrupts to tell Mr. Burns that Archduke Franz Ferdinand had died, and what happened afterward. Burns has lived nearly a full-century on the planet, and had no idea that either World War had taken place.
To The Godfather at the end, when Burns pleas with Mark Cuban to vouch for him after revealing he's a millionaire rather then a billionare. Cuban tells him he can't do it.
Also, to WALL•E when Homer imagines a world without honey.
One of the games played at the billionaires' retreat is Quidditch.
When the bees take over the stadium and Bumblebee Man claims to be one of them, one of the bees says they hate him the most and calls him "Uncle Tom".
Simple, yet Opulent: The billionnaire camp doesn't seem that flashy at first glance (Burns do a typical food fight with ketchup and mustard) but a lot of the activities there are decadently expensive, such as roasting jewels, shooting valuable paintings or playing Quidditch.
Writing Around Trademarks: The professional basketball team that The Rich Texan loses to Mr. Burns in the poker game is conveniently called the Austin Celtics. The team's logo◊ is slightly tweaked from that of its real-world counterpart. Of course, Burns subsequently relocates the team to Springfield, and renames them the Excitement.