According to Taiji's book which I read fan's translation. He knew the bad news by the media report. Taiji went to Hide's funeral by himself. It's Yoshiki who noticed Taiji was there and greet him well. J-media reported Taiji attended the funeral, just simply.
Frankly, I've never thought Taiji is closed to Hide's family at all, as far as I read both Taiji's and Hide's interviews. They lacked of talking about each other, if the topics weren't related to the band. Even now, Taiji's blog has never written anything about Hide's family nor Hiroshi.