There is a lot riding on this M1. You must protect yourselves.
I would make it very clear it is still a prototype and "subject to change" and that any public review mentions that right at the start otherwise it could harm your sales as potential customers could think that some random edited re-tweet is about a shipped final version.
In fact if it was me, I would make M1 testers sign an NDA and consider it a closed beta, then let others "review" the headset after it launches shortly after. Nothing good has really come out of a "public" pre-production review other than a hold-no-prisoners critical analysis. For example, something simple could have been left disabled in the hmd driver that gives a horrible experience but is a 5 minute fix, this could be too late as somebody has already tweeted about it before running it by Pimax.
Or at the very least Pimax must approve any public review to save themselves from any misunderstandings.
Also, set a "no earlier than" release date of any reviews so people are not rushing to publish first.
Just my 2p