Russian here. This is a super old claim from our government and is a common source of jokes, it’s even called “Cheburnet” (from Cheburashka) colloquially, nobody really treats such claims seriously. Last time Russian government tried to influence internet was when they struggled to ban telegram for several years, and ended up giving up, endorsing it, and moving their official resources to it.
One thing I always talk about is how DE is much more important for new user than a distro. New users will only use GUI anyway so their choice of DE has to be the most comfortable.
Took me years personally to switch to Linux, trying stuff like Ubuntu or PopOS, and I couldn’t understand why it doesn’t “click” for me until I understood that I simply personally dislike Gnome (being an ex Windows user). Tried a KDE distro and it clicked immediately, never looked back. Now I don’t even use KDE but it helped me to get through initial frustration period.