For sure, there are some crazy ppl out there who celebrate bad things. On a positive note, I don't think there was a single prominent figure (anywhere on the political spectrum) who did anything but immediately condone the murder.
Lot of crazy incels sitting in their parents basements along with plenty of russian/chinese bot farms that make you want to believe people are broadly celebrating this murder.
I don't know about you, but I personally don't know a single person in real life who celebrated the murder or who even thought it was net positive regardless of their political leanings.