GIA do in fact still list Daniel Elder, and suggest hiring him for commissions and masterclasses.
I see that they characterised a post against arson as "incendiary", you couldn't make it up.

Good catch. His stuff is still for sale there as far as I can tell. Did they kiss and make up? Was it just bluster to appease the Twitter Weirdos? What's going on?

It's very possible they quietly reinstated him once the heat was off. They pulled Paul Tate's music a couple years ago for reasons not entirely specified (but hinted at misconduct), and his music is once again available from GIA.

My diocese's annual appeal promo video uses the song "Glory and Praise to Our God" as its theme and background music.

Sigh.

Maybe they are clever like a fox and are deliberately appealing to the nostalgia for the 70s among the geriatric donor class.

But as a song choice? Music like that should be retired. The under-40 Catholics will hear that and many will be annoyed. Some of them will even wonder what the heck that song is. I never program it at my parish.