So as I understand it...
 

EVERY Single HM so far, is known by at least one other... I really thought it might be different this year with 'complete' unknowns but I suppose not...

Oh well, still give it a chance watching it w/ literally no feed outside of what the bosses at C5 want us to see.

I think because of the audition process it's inevitable that some of them will have met before.