Q. Can an onen (one who lost a close relative, before burial) partake at the seuda (meal) of the bris of his grandchild? If yes can he be asked to speak publicly. (See question 2514 above).
A. Horav Shlomo Miller's opinion is that although an onen in principle can eat a meal with others, he should abstain from attending a happy celebration as in the case of a seudas simcha fpr a bris, where he is bound to be greeted and saluted with expressions of joy and mazal tov.
He should also not speak at the seuda even if he just enters for delivering his words or in the shul after the bris, since he is prohibited from learning and teaching divrei Torah. This applies even when the body of the deceased has already been transferred to the Chevra Kaddisha, (See Shulchan Aruch Y.D. 341: 1).
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit'a