If true it may be like certain Furbys. There are Furbys made by a specific factory that are plagued with problems. Speakers going out, movements going out of synch, gears making grinding, screeching noises and things like that. The limited edition Tropical Furbys were almost all made in that particular factory and are almost all plagued with problems. Maybe the yellow and white ID Ls are made in factories that's quality control isn't as good as factories that make the other colors. Or it could just be a coincidence that yellow and white ones seem to have a higher rate of failure.
I tend to avoid white virtual pets anyway. Unless extremely well cared for, white plastic tends to yellow after about ten or fifteen years. And even if you take precautions to prevent it it can still happen. There are plenty of Star Wars Stormtrooper figures from the 70s and 80s that now look like they peed themselves. I do have a white TamaGo, and because I'm attached to him I don't regret buying him, but he'll probably be the only white Tama in my collection.