The situation as regards Gibraltar actually does have parallels with Guantanamo Bay - especially if the occupation of the latter continues, and the naval base gradually becomes marginalised, surrounded by an American civilian city, which no doubt in any referendum would vote against being handed back to Cuba. (Incidentally, it's not "Guantanamo" - that's a city within Cuba proper. It's Guanatanamo Bay.)

Rectifying historical injustices has to have its limits. Gibraltar was unjustly seized and held, regardless of the wishes of the inhabitants at the time, and the same goes for the Falklands/Malvinas; but the same is true of the entire territory of the American continent, North, Central and South. The balance of justice has to be to respect the current wishes of the people, and in the case of the Gibraltarians, that is not to be absorbed into Spain.

Whether that implies a permanent right to be linked with the United Kingdom is another matter. They've never been offered the alternative of independence so far as I am aware. (And my suggestion that it be allowed to remain a British enclave, balanced by an equivalent Spanish enclave in England is actually genuine, though of course it won't happen, more's the pity.)