Being 'listed', to my understanding, means being included on a list of deities that includes that deity's domains
You may be correct, but in that case there would be no need for this part
The same rule does specify "f your deity doesn't include suggested domains in the resource in which it is found, only the Life domain is available." (ALPG v7.0, p.3)
If there is no domain suggestion, by your definition a deity is not considered to be "listed" so it's not available as a Cleric patron.
Regarding lore, the sidebar in SCAG points out that "What were referred to as Chosen in other lands, were recognized in Mulhorand as living gods, come to lead the Mulhorandi in an uprising.", so even if the demigods themselves may not serve as clerical patrons, the deities whose Chosen they are, might.
Anyway, Travis' "behind the scene" insight is enough for me to accept that the intent is for Mulhorandi gods not to be available as patrons, and I'm happy to let the matter rest.