If you browse other regions of China there, in some (mainly the ones whose names I didn't recognize which I expect are the most provincial hence why I've never heard of them), you will find a fall in birth-rates from aproximatelly the same values to the same values (i.e. around 1.4 to around 0.6, for example https://www.ceicdata.com/en/china/population-birth-rate-by-region/cn-population-birth-rate-jiangxi and https://www.ceicdata.com/en/china/population-birth-rate-by-region/cn-population-birth-rate-shaanxi) but none but Xinjiang have that steep drop in 2017.
Something happenned in Xinjiang at around 2017 and for at least a couple of years that did not happen in the other regions of China.
We can't really deduce anything about what's still happenning there, either way, from that graphic.
EDIT: There is a response to this post where a link is provided to a report by a Think Tank created by and openly funded by the Australian Government (as shown right there: https://www.aspi.org.au/about-us/, second paragraph). The post were I pointed out that such a source has a conflict of interest, hence that report can't just be outright trusted, has been moderated away as "misinformation" even though my claim is proven by their own website. Feel free to draw your own conclusions as to why such a comment was removed by a moderation action backed by a false justification (as the page above proves), especially in light of the specific subject we're talking about here.
I think the current bunch and their idiot flunkies are already the kind of people one would not want to have access to any information that could be used to blackmail or harass a person.
People who have old ladies arrested for demonstrating against mass murder of children due to their ethnicity, are NOT morally upright people who when in power would never abuse information about who watches what porn.