I'm going to chalk this one up to probably makes sense without even asking the question.
I'm making an assumption that while in a squad of players with a mix of regional accounts, the player that launches a search for a match will search within their own region's servers.
As mentioned previously, though in the UK, I have a US account, thus I'll hook up with US server matches. Should I have someone in my squad with a UK account in the UK (or US for that matter) and they launch a match, we'll be looking at the UK servers (or EU servers...where ever they're located).
I'd imagine this is a PSN specific thing, not a Dreadnought thing.
I suppose in some respects, this could be a way to get around the I'm in the UK but stuck on US servers problem if true.