Q. The seuda – meal offered after the chalaka or the traditional cutting of the hair when a boy becomes three years old, is it considered to be a seudas mitzva? (for the purpose of the effort in attending and washing hands or eating meat during the Nine Days).
A. Maharam Brisk (2: 98) and others maintain that the meal is similar to the seuda of a bris. Other Poskim also opine that one should celebrate the event with a festive meal (Sdei Chemed – Beis Haknesses 10, Kesser Shem Tov (1, 690), Even Sapir 2: 47, and others). One of the main reasons is that it is an occasion dedicated to the chinuch of a child.
Shaarei Teshuva (531: 7) recommends one should wait until Lag Baomer, to increase the simcha with the joy of that day.
Horav Shlomo Miller’s Shlit’a opinion is that it depend on the minhogim and traditions of each family and congregation, but it is certainly recommended to say divrei Torah at the occasion or making a siyum when possible.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a