Seems like a very bad idea to announce the capability and means for defeating an enemy weapon. Which makes me suspect this is misinformation or a psyop.
Eh, it's at such a superficial level it doesn't really pose a problem at the "revealing secret capabilities" level. It's EW, and Ukraine is covered in EW. If it's working against Kinzhal particularly, Russia doesn't need to read random English blog posts to find out. So this is just fluff propaganda or something. It's not that deep.