I believe that the author is literally polyamorous, has a community of romantic partners that they refer to as a "polycule", and wishes to operate a VPN exclusively for members of that community.
Haha well, in defence of the site, it’s literally just me who got it wrong. Other people downvoted my initial comment because it must have been obvious to them.
I have to say I was a little afraid at the end that I might have inadvertently offended someone.
I don't think it's meant as a metaphor.