Not exactly. The Maytag Corporation DID hold the trademark registration for the name "ROCK ISLAND" and the familiar railroad logo, specifying that the trademark would be used for "toys, namely, miniature railroad engines and cars" but the registration was cancelled on January 22, 2005, and is now dead.
Maytag Corp. also applied for a second trademark registration for the name "ROCK ISLAND" and the logo -- which Maytag claimed it would be using for "railroad services and transportation of persons and goods by rail" and "board games, puzzles and models", but after receiving several extensions of time to file a statement that the trademark was actually being used for those purposes, the registration was deemed by the Trademark Office to have been abandoned. It's also dead.
The only live trademark for "Rock Island" is owned by one Charles Callaway, who uses the name to sell clothing and tavern services. It includes no logo and has nothing to do with railroads.
In any event, the Rock is not a UP predecessor, as the UP's Brenda Mainwaring has conceded ("Rock Island is not part of the Union Pacific family of railroads and Union Pacific lays no claim to the Rock Island trademark"). As I understand it, the ICC had approved a UP-CRI&P merger circa 1974, but UP withdrew its offer for the CRI&P, which then went into receivership, ceased operations circa 1980 and then sold assorted parts of its ROW to several other railroads. Many of those "parts" have now returned to the UP's fold, but not the railroad itself.
I hope those "investors" who bought Maytag weren't expecting to go into the railroad business -- real OR model.