The public announcement is here: Download Philosophy Public Affairs Public Letter of Resignation -. PPA was also a Wiley journal (like the now-defunct Journal of Political Philosophy), and comments by the EIC of PPA in 2023 foreshadowed this development. (The EIC has a separate contract with Wiley, and was not part of this mass resignation.) Whereas JPP was founded and strongly identified with its lead editor, Bob Goodin, PPA has been around for a half century, and none of the current editorial team founded the journal. But their mass migration to a new journal should suffice to sustain the reputation of the PPA successor journal, as of yet unnamed.
As we learned during the JPP crisis, not all editorial experiences with Wiley as a journal publisher have been bad. Wiley still publishes a number of other prominent philosophy journals, including Analytic Philosophy, European Journal of Philosophy, and Philosophy & Phenomenological Research, among others.
ADDENDUM: One of the resigning editors tells me that, "The founding editors (including Marshal Cohen, Tom Nagel, and Tim Scanlon) were consulted about this decision and have given their full support to it."