It had a Sonic room in it that prominently featured not only the Hedgehog himself but a Mega Drive console and controller. There was game footage in there which featured Sonic 3 which was released in May 1994. The second half of Sonic 3, Sonic & Knuckles was released in October 1994.
The Mega Drives successor, the Sega Saturn, was released in Japan in November 1994 and in the UK in 1995 with the Mega Drive being discontinued shortly after. The Saturn's successor itself, the Dreamcast, was released in 1999 (with Sonic Adventure being a release title for it and Sonic Adventure 2 coming along in 2001) and Sega left the console market entirely in 2001.
So between the room being built and the rides closure, Sega had released and discontinued 2 successor consoles, left the console market entirely and released 5.5 (3.5 mainline not including Sonic Jam) Sonic titles from that featured in the room. The Sonic room was out of date by the beginning of the 1995 seasons let alone the 2005 season!