Ideally that might be best but it's not going to happen, if they can make a bit more money they will.
I do think £8,50 is too cheap, the Epicurean breakfast should be more than £8.50 better than the MDR. My biggest objection would be not about letting others in, but that the exclusive suite breakfast should be worth at least £20 extra, better ingredients more dishes not available elsewhere, all cooked to order with the ability to tailor it to individual. If its only worth an extra £8.50 then it doesn't live up to promise
My other concern is that this policy doesn't impact me. I liked it in Aurora when you got to know regular breakfast neighbours, and you also had same waiters every day. This can be achieved by reserving an area solely for Suite passengers, this should of course be best tables with best views. Any non suite demand needs extra staff.