I am really curious how much of interaction did designers have with the Deaf community. Did they ask Deaf persons to go thru their materials and so on?
I have seen Deaf community, culture, and language fetishized by the hearing people for profit and I'm tired and sick of it. One co-designer is from Bay Area which has a large Deaf community with American Sign Language (ASL) poets, storytellers, and activists. We haven't heard of them at all which suggests to me they haven't done their proper research by coming out and talking to people who actually uses ASL.
Some of you may go but but they don't know how to reach out or whatever. Just google "Bay Area Deaf." There is a state-run school in Fremont for the Deaf which has tons of resources they could use as well as people who are actually way more qualified than them to discuss ASL and signed languages.
Purchase this if you want but be aware you may be complicit in taking advantage of a marginalized group of people.