I grew up in Wrexham, and can tell you without a shadow of doubt that there has always been a large RL following in the town (hence my interest in their impact on SL). I knew as many english as welsh when I was growing up on the outskirts in the late 70s/early 80s.
And yes, I would see Oldham go to the wall. I'd also see Leigh or Widnes go if there was the obvious lack of interest in the game in the area as there obviously is no interest in the game in Oldham, certainly compared to Wrexham or Catalonia. I wouldn't say I'd be happy to see them go but you can't keep throwing money at clubs that are failing, its no wonder the RFL is only just turning its finances around after years of paddling a holed canoe.
I'm not saying that Broncos are my ideal team, but at least I can understand that without a London club, there will be no Sky money. Without Sky money there will be no SLE. Without SLE, RL will continue the slide into obscurity that had started before its creation. So a London club is a necessary evil in the game.
Conversely, Catalan and Crusaders (to date, I'm not shouting too loudly about Crusaders crowds yet though, give it a second season of good attendances) are showing that you can grow the sport outside it's recent heartland core. So two out of three successes, with one necessary evil isn't a bad result.
Incidentally, I used the word "recent" rather than "traditional" as it is only the post war era where the game has retreated to the North of England. The expanisionists are just reclaiming historic bases.