The first consumer smartphone to run lineage out of the box is a bogus claim. I personally owned a whileyfox for some years which I bought only because of that.
The first one might be because companies that make a big deal about being pro diversity have already identified a problem and are trying to combat it by making big deal (not necessarily by doing anything else), whereas normal companies don't need to advertise that because they already have a wide variety of employees.
I'm not sure open sourcing entirely solves the problem, that doesn't show how the company has the software configured. I'd suggest that you need rigorous and continuous independent auditing with results published. But where do you get that these days?
The trouble with waiting to see is that once you've discovered that it is being abused, the system is already in place and hard to remove. Additionally, it's a kind of frog boiling situation where the more such systems you have the more acceptable further such systems and abuses are both in the comment and socially.