I call BS.
You know why they don't voluntarily pay higher taxes, and yet advocate for it? because they know if the tax rates/laws change, they will just pay their lawyers extra money to figure out how not to pay it - they want someone else to do it instead.
Same reason Bezos preaches on GW, and yet drives around in a yacht that burns more fossil fuels than thousands or of typical Americans will use in a year.
It's all virtue signaling, and nothing else.
She's basically advocating for policies that would make it impossible (or extremely difficult) to become and remain as wealthy as she is, let alone a billionaire. And she's directly going against her own financial interests with this because no amount of creative accounting would shield her from all of it if it became actual policy.
For the record, I remembered her being a billionaire heiress but it seems I was off by a digit or two. So I apologize for incorrectly referring to one-percenters when I meant mostly her and other millionaires (afaik) who support her project called Taxmenow. She also criticized philanthropy.