The Matrix.org is Community Interest Company registered in UK, and its full name is THE MATRIX.ORG FOUNDATION C.I.C., please, consider this as a proof proof.
Given this information, I would guess it's relatively safe to donate/give funding to the Matrix.org because its financial flows should be protected by UK law.
BUT, it seems they never made a full report of incomes/spendings, the first one is expected in April 2024. But it's already April 2024, and I don't see a report. Anyway, it's better to read original Issue in regard of such things, I might understood it incorrectly