This article shall not be construed to do either of the following:
(a) Preclude or limit the ability of a developer to seek a density bonus, including any concessions, incentives, or waivers of development standards, from the local government pursuant to Section 65915 or any other local program that offers additional density or other development bonuses when affordable housing is provided.
(b) Expand or contract the authority of a local government to adopt or amend an ordinance, charter, general plan, specific plan, resolution, or other land use policy or regulation that promotes the development of supportive housing.