In fact 4 displays in total was publicly shown 2 years ago: From the Hackdesk: Librem 16 - #5 by jonathon.hall
There is no rigorous scientific answer to the question as to whether Purism is making a specific point of it.
Yes, it’s true that you would have to read between the lines of the specific blog post.
I am unconvinced that it could be justified having 2 full-featured USB-C ports (as mentioned in the blog post), hence display output via either USB-C port, if you couldn’t use the USB-C ports simultaneously for video output (unlike the bad old days when, as you say, the multiple video outputs tended to be alternatives and really just a convenient way of avoiding having to use a video adapter).
So I have taken all the available evidence:
- the public commentary 2 years ago,
- the specific text from the blog post that you quote yourself, and
- the Intel CPU specification on the Intel web site (which says 4 displays supported)
to make the claim that
in this case it actually does mean that.
@jonathon.hall Perhaps the tech specs at Purism Librem 16 – Purism could be updated to cover the specific point regarding external displays i.e. make it more explicit than just mentioning under “Video”: 1 x HDMI and 2 x USB-C - and really the product blurb on that page more generally should mention external displays explicitly, as not every potential customer configures laptops in their sleep. 