our closest LS mate came out as poly and the whole group dynamic shifted

so one half of a couple we've been close to for years came out as poly recently. they've been swinging for a decade but now hes saying its more than that for him, he wants ongoing relationships, his wife is processing it, the group is processing it. we're all 100% supportive but its changed the dynamic. who he plays with at parties now feels different. some couples are pulling back without saying anything. is this normal when someone in a long term swinging group transitions to poly? how do u keep the friendship strong thru this kinda evolution