The US is trying its best by kicking 170 million users out of their prefered app. Amazing that I haven't seen more effort to pick up the refugees. Twitter could've made a big video push. Tumblr (I know photomatt is a little distracted now) could've reminded the world it exists. etc.
That could definitely be it. They might also be trying to play it cool, and not appear to gloat before the corpse is even cold. Instagram is running a lot of ads on TikTok now though.