Kamala Harris just want to avoid unnecessary damage for her support before the election. She will choose events where she can show her strength, not weakness. In Bitcoin Conference, Kamala actually does not have good opportunity to deliver convincing speech and she will like fail against Donald Trump.
Smelling this risk is enough for Kamala to stay away from Bitcoin Conference this year because should never join it and say things oppositely to what she did previously months before taking over the nominee position from Joe Biden.
I am honestly bored of the Trump and Bitcoin talk, but I can also admit that the Biden administration with Kamala Harris as vice has been anti-bitcoin for the most part of it.
It's another reason Kamala should not join the conference, at least don't join it will help her to avoid additional damage on her election program for very last months before the election. She accept to give up this conference and only can hope that Trump won't successfully convince many participants there, but it's less likely Trump will fail with his speech ability.