So... first off, shame on me for not reading instructions and not properly testing. This is from a separate account.
Unfortunately, in my rush to test SAML configuration, I didn't setup a user outside of SSO or leave a window open with an open session.
I then configured SSO incorrectly, and have now locked myself out of all Atlasssian cloud services, including support. Those few who had support access are also locked out.
Any ideas?