What the link actually says (emphasis mine):

"Rajendra may have named the city Singapura (“Lion City”), later corrupted to Singapore, or the name may have been bestowed in the 14th century by Buddhist monks, to whom the lion was a symbolic character. According to the Sejarah Melayu, a Malay chronicle, the city was founded by the Srīvijayan prince Sri Tri Buana; he is said to have glimpsed a tiger, mistaken it for a lion, and thus called the settlement Singapura."

I don't see any other sources attributing the naming to Rajendra Chola I. The name change from https://en.wikipedia.org/wiki/Temasek to Singapura is generally noted as occuring in the 1300s, centuries after his forays into the area. Most attribute it to [https://en.wikipedia.org/wiki/Sang_Nila_Utama](Sang Nila Utama), though some scholars contend he didn't even exist. There seems to be general agreement that "lion city" is indeed the meaning, though there are several other proposed etymologies, and how it came to have that name is far from settled.