I'm reading many comments on the main post. To clear a few things up, the US IRS decides, "yes or no" if something is a NPO & that's it. No control, no operational involvement, etc.
Under the Internal Revenue Code, only U.S. NPOs are eligible to receive tax-deductible charitable contributions from U.S. taxpayers.
If I donate to a non-US Mastodon NPO, I still get taxed.
If I donate to the US Mastodon NPO, that money isn't taxable when I file my US taxes.