Did Uncle Lao Luo take Xiao Gazi to the teahouse for tea?

No, in Private Zhang Ga, Uncle Lao probably wanted to let Xiao Gazi experience traditional culture and exchange information and experience with others by taking him to a teahouse. Moreover, Xiao Gazi is young and may have insufficient social experience. Uncle Lao Luo took him to the teahouse, which allowed him to get in touch with more people and things, thus cultivating his social skills and coping ability. So the old uncle didn't take Xiao Gazi to the teahouse for tea.