I grew up in Shanghai from 1994 - 2013. To go through your points: 1) media in local languages is allowed and state-funded in Shanghai, 2) Kids did speak Shanghainese in school, though official instruction was in Mandarin, 3) Official documents can't be translated into Shanghainese since it's not written, 4) there is institutional support for cultural preservation - as I write below TV shows are in Shanghainese / Wu, announcements on buses and subways in Shanghainese, there are free Shanghainese classes you can attend, radio shows (all state-backed) that are Shanghainese only or have Shanghainese / Wu radio shows, 5) Shanghai's Religious Bureau was pretty good, I went to 3 Catholic churches in Shanghai growing up, they had Masses in Mandarin, Shanghainese (harder to do now since most priests in China come from smaller, extremely Catholic Villages, not as many from Shanghai), and English. The city gov't gave money to help restore / renovate the Shanghai Cathedral (if you're there you should go visit, it's in Xujiahui) - unclear about other ones but I've been to Protestant churches, been to one Mosque. There are 80 million Catholics in China now, so I think it counts as a minority religious faith.
So to your points, the only one that Shanghai did not fulfill would probably be the "allowed to attend schools speaking their native languages" part. I'm not sure I think Shanghainese should be, maybe it should have a formal class? There are free classes you can take (usually by District), and everyone spoke Shanghainese at home, so I'm not sure it's necessary.
If you go to Shanghai, buses and subways announce in three languages: Mandarin, English, and Shanghainese. I was just there beginning of October and yes, not all buses had this but it was prevalent enough. This means they are promoting the Shanghainese language (a subset of the larger Wu Chinese dialect). There are TV shows in Shanghai / Jiangsu / Zhejiang that are solely in the Wu dialect - and this is not recent. I remember watching shows with my aunts and uncles 15 years ago. XinMin Evening News always had some cartoons (think New Yorker cartoons but not as highbrow) with Shanghainese dialect subtitles (as in Chinese words that most mimic the Shanghainese dialect).
If you go to Guangdong or Guangxi, many people still have trouble speaking Mandarin, especially outside of bigger cities like Guangzhou. In 2010 I was doing some volunteer work in a tiny village a few hours from Guangzhou and the kids we met literally did not understand Mandarin. The CCP struggled really hard to make schooling in Guangdong province taught in Mandarin (but succeeded by the 80s-ish, again, only in bigger cities). Now though, more and more schools are starting to do Cantonese classes with their own textbooks, alongside the standard Mandarin education.