Thank You. (And it's not just the fanbase, btw, it's also the people who play and administer the game in NI, too).
Any chance you could stop there?
Obviously not, then. Oh well.
I might have guessed something like this was coming...
Anyhow, if you are going to speculate on what might/might not happen, you would be advised to get your basic premises right, at least.
First, the BC was not a competiton between "the four nations etc", it was a competition between the representative teams of the four Associations. (And speaking of "representative teams", up until 1950, the IFA's team was drawn from the whole of Ireland, afterwards it was drawn only from NI)
Second, any such tournament is not the property ("theirs") of the FA to organise. Instead, it will be a collaboration between the four British Associations, who will decide between them.
Finally, if the FA doesn't like what the others agree, it is for them to withdraw (as they did with the BC in 1984), or decline to enter (as they did with the Carling Nations Cup). Similarly, it is for any of the other three Associations to decline to participate (just as they all did with "Team GB" for the 2012 London Olympics).
Anyhow, if the four Associations should decide to play each other in 2013 (or whenever), that may properly be termed a revival of the (former) British Championship and it would be appropriate (imo) for the old trophy, currently in the possession of the IFA, to be up for grabs.
If, however, they decided also to invite a fifth Association (namely the FAI), then whatever else, it could NOT be considered to be a revival of the former BC, it would have to be called something else.
As a traditionalist, I would prefer to see the former; also because it would have the side-effect of excluding the (cash-strapped) FAI from participating in a potentially lucrative money-spinner. And a four team/six match tournament might be more likely to be repeated every two or four years(?) than a 5 team/10 match tournament, which I suspect could only be a one-off, due to fixture congestion etc.
That said, if they should come up with a "Five Nations", I would still support NI's participation in it, so long as it wasn't being hosted by the FAI.