I agree, this is a much more important issue as far as duplicate rides are concerned. My first theme park experience was DLP. Rather than stopping me going to Orlando because I'd already seen a version of the Magic Kingdom, it encouraged me to go to Orlando because there was so much more of that theme park excellence on offer. If Orlando had been my first experience, would I have gone to DLP? Maybe not, especially as I might have concluded that I'd already experienced everything that Paris had to offer while I visited Orlando.
I think too much concern is being attached to the cannibalisation issue. Yes, lots of Brits visit Orlando, just over 900,000 last year, but the UK's population is 69 million so Universal is creating a massive new market of potential visitors by building in Bedford. The possibility of Orlando losing a few British visitors is pretty small beer compared to the domestic audience that Universal is hoping to attract in Bedford, and that's before you start thinking about visitors from the rest of Europe.
If Universal want to minimise the possibility of Brits deciding not to visit Orlando because they've "done it all" in Bedford, there is pretty easy solution to that potential problem. Build world class and unique attractions, which reside within beloved IPs. It's what they've done extremely well over the last 20 years, as even the most cursory glance at their track record will show. So it should be business as usual for Universal Creative, the only thing which will hold them back is a lack of ambition (and investment) by UDX and Comcast.