I can't see twitter in this browser with the anti tracking etc stuff I run, but, having seen similar posts elsewhere, there was suspicion that it was one of the feeder lines, and it's already extinguished.
There are also tweets out there saying the separatist leaders both filmed their evacuation videos, mentioning the February 18th date a few days ago - tiktok keeps the metadata.
Again there are also tweets out there suggesting military vehicles have crossed from Russia in to separatist controlled areas.
As far as I'm concerned, a Russian military operation has started, and I think Vlad is going to try to get all the way to Dnieper and take Kiev.