We just recently landed the GNOME 3.34 stack in the unstable repository, and while the feedback in the task has been promising, sync is going to be deferred until next Friday to ensure enough time is provided to find and resolve issues, as well as validate the upgrade path with more of our unstable repo users. This will also provide us more time to resolve NVIDIA-related issues with the new Linux kernel 5.3.1 in the unstable repository.
This is a fairly standard (and anticipated) procedure for large stack upgrades of this nature as we work to provide you a stable, curated rolling release operating system.
I'll be putting out a blog post next week prior to the sync to provide our users news about the latest changes in this stack upgrade, information on any known issues at the time, provide people a warning to disable GNOME Shell extensions not shipped by us, etc. so keep an eye out for that!