Is it obligatory to cut ties with the deceased wife's family after the husband remarries, and to prevent the new wife from visiting them?

It is better for you to continue visiting your deceased wife’s family, because this is a form of maintaining good ties, which is a sign of faith, as the Prophet, peace and blessings be upon him, did with the friends of Khadijah, may Allah be pleased with her. As for your current wife’s jealousy, it is natural, and try to convince her that these kinship ties are Islamically required, and she has no right to interfere in them.