It is still illegal to produce or own cannabidiol derived from Marijuana. Emphatically, this statement from the FDA does not mean that cannabidiol as a chemical is legal.
(2016, usdoj.gov) https://www.deadiversion.usdoj.gov/schedules/marijuana/m_ext...
Nothing has changed here except that the FDA is claiming authority to regulate the small subset of CBD products that are legally produced from hemp. The above DOJ article goes somewhat into the science of how these products, if they exist and are produced legally, contain such trace amounts of CBD that they're surely ineffective. Point being: either it's produced from real flowers and it's still illegal, or it's produced from hemp and present in such small amounts that it's of absolutely no benefit. The FDA is merely saying that they want to regulate the latter case.