I don't think disclosure is the only purpose that is being served.
To me, there's some vanity in play here. At the expense of poking the hornet's nest.
It's obvious Ukraine is getting a lot of support from the US. Letting the Russians know what you are doing makes it easier for them to find ways to disrupt it.
Also, the Russian narrative that they are in a proxy war war with NATO, when a few days ago everyone was denying it, now has stronger support.