Hard to say, but there's a huge brightening perpendicular to its trajectory so this could be it falling apart... I'm not sure, just asked Emily what she makes of it on Twitter. There seems to be some flare (solar proton event) just in front of it so it could have hit a higher pressure wall and we see its forward corona, i.e. its coma flattening due to pressure... I still see a bit of its nucleus ahead of that, so it might be just an outburst