Even if the Bundesrat blocked it, which I am sceptical, the current figures do not lie. See infographic that shows the majority of applicants in 2017 from every single continent received dual citizenship.
https://www.dw.com/en/dual-citizenship-granted-to-most-naturalized-germans/a-45030118
Berlin Senat is also going to make it easier for Berliners to acquire a German passport, too.
https://www.berliner-zeitung.de/politik-gesellschaft/integration-berliner-senat-will-mehr-als-400000-auslaender-einbuergern-li.228868
Obviously, it's better if it were codified, as it would make things more certain, but the rules have not been strictly applied for years now, and are clearly going to get even more lax in this area irrespective of what the Bundesrat wants. There's no need to be all doom and gloom about it when the direction of travel is clear.