It's the "I have a reasonable expectation to use any loo should I require" , that puts I and perhaps others on an anti stance though.
If you are that desperate then yes goodness, I'm not expecting you to pee yourself - when I was in the cabin I ushered many an elderly person or child up to a free bathroom, but what you are saying smacks a bit of "I'm coming through and blow the rest of you and what you think".
And if you work in the industry shirley you realise that airlines sell premium products with the expectation that the products are not mixed, otherwise the point of paying more is somewhat lost.
As for an upgrade - if you get one bloody well enjoy it sir.