I don’t see any restriction for a 501/3 to talk to regulators.
Organizations described in section 501(c)(3) are prohibited from conducting political campaign activities to intervene in elections to public office.[26] On the other hand, public charities (but not private foundations) may conduct a limited amount of lobbying to influence legislation. Although the law states that “No substantial part…” of a public charity’s activities can go to lobbying, charities may register for a 501(h) election allowing them to lawfully conduct lobbying activities as long as their financial expenditure does not exceed a specified amount.[27] 501(c)(3) organizations risk loss of tax exempt status if any of these rules are violated.[28][29]
A 501(c)(3) organization is allowed to conduct some or all of its charitable activities outside the United States.[30][31] Donors’ contributions to a 501(c)(3) organization are tax-deductible only if the contribution is for the use of the 501(c)(3) organization, and that the 501(c)(3) organization is not merely serving as an agent or conduit of a foreign charitable organization.[32] Additional procedures are required of 501(c)(3) organizations that are private foundations.