I don’t think your scepticism has much merit; others can of course read the status on the crowd funder and draw their own conclusion. As an aside from the conversation I would pay £675 at entry level: it would appear that dollar has tanked against the British pound and Euro even worse than I thought. So your weak currency seems to make the prospect steeper than it would normally be, and I hope you considered this.
I disagree that it the offering is especially radical - there is a long heritage of linux smartphones, perhaps the Pinephone is best known. It is certainly not for everyone since the popular “app stores” will not support it, but linux phones are hardly an unknown quantity, and have their adherents. For those in the market for a GNU/linux phone, this seems a very strong option.
The hardware strikes me as having similarities to the MNT Reform family of laptops, particularly the choice of 3588 processor which does very well in that application. So much for everything being a leap into the unknown. This makes me hopeful that we see Genode Sculpt ported to it sometime, as I find that more interesting than linux. Sculpt is available already for the Pinephone and the Reform, making the NEXX an obvious target.
Liberum may not be the next big thing but would be a welcome addition to a growing scene of niche European hardware manufacturers like the aforementioned MNT.