Thanks to a heads-up from madfilkentist, I can now confirm that LJ's servers were, in fact, moved to Moscow. The lag was presumably due to DNS propagation delay, which sometimes takes up to a week.
Geolocation data from IP2Location (Product: DB6, updated on 2016-12-5) Domain Name Country Region City mdlbear.livejournal.com Russian Federation Moskva Moscow ISP Organization Latitude Longitude Rambler Internet Holding LLC Not Available 55.752220153809 37.615558624268 (End of the road for LiveJournal [The Mad Filkentist])
See also my previous post on the topic, mdlbear | Dirty deeds afoot on LJ
One thing I forgot to mention: after you've set up an account on Dreamwidth, you should claim your Livejournal OpenId. That links your DW and LJ identities, so that anyone importing data from LJ will see comments as coming from your DW account even if you wrote them on LJ.