Bullshit. There are tons if Imagination GPUs with no free software driver.
Technically they didn’t specify that all Imagination GPUs support it, only “Imagination GPUs” plural. Could be as little as two.
In English in England, that sentence reads as meaning all Imagination GPUs. Were it less than all GPUs, one would expect “Some Imagination GPUs” or some other qualification.
The contrast between the two forms gives the impression of deceptive marketing. And that’s what it is.
Bigly huge. The age of translation layers are upon us!