The vast majority of generators of fake news today are from Content Mills, Copy Paste Mills and general SEO spammers. Political misinformation is the other big generator. The economics of it and not "ethical" gate keeping is what will affect their output. Realistically, normal people don't have the ability to coordinate hordes of proxied IPs to attack social networks requiring account sign ups and custom feeds.
The value of exercising critical thinking, checking trusted curated sources, information hygiene, recognizing and avoiding manipulation tactics in news and ads will have to go up. The internet is already almost entirely unreliable without requiring any fancy AI. The listed skills will be necessary regardless any increase of politically manipulative content, advertisements or product misrepresentations.