It is completely understandable for Blender.io to rebrand and relaunch under a new name Sinbad.io. There's nothing surprising with that; they want to get around sanctions. What's ironic is that they are into a business of erasing tracks, of wiping out traces which could lead to any user's identity, of privacy in other words, but they somehow failed to do that themselves. That Sinbad.io is the old Blender.io may or may not be true at all, but with all the coincidences mentioned by LeGaulois it seems they failed to clean their own tracks.