All you need to do to refute the shit spewing out of Eric's mouth is look at the books: blacks are overrepresented, as are non-human races.
One writer (a term I use as loosely as SJWs throw around Nazi) pledged to push homosexuality in every product, a practice he thinks is both unconventional and progressive despite homosexuality being pushed in everything else. They hire to check off diversity boxes instead of talent and skill (and boy oh boy does it show), and I wouldn't be the least bit surprised if they covertly engaged in discriminatory hiring practices.
If WotC were really trying to push a straight, white agenda, for starters they would at least somewhat properly represent skin color, and go out of their way to ensure that every NPC is straight (regardless of whether or not it matters to whatever terrible adventure they're pushing).
For a secret Christian agenda you'd have angels looking like Christian angels. You'd have references to Christian angels and demons. You wouldn't be able to play wizards at all (or druids or warlocks). There would be inherent benefits for being religious, and only the Christian God would be acceptable.
It's almost as if WotC is bending over backwards to pander to every demographic but Christians (and normal people in general).