dunno really.
'nationalism' covers quite a range of things - there's the sort of nationalism that involves maintaining / reviving / promoting a national / regional identity (language / culture etc?) within a larger current nation state, and at the other end of things, there's the sort of nationalism that is anti-immigrant and all that goes with that.
and what's called "the gay community" is nothing like one single, homogenous group (and that's before you get in to the question of to what extend it does or should include bi people, lesbians and gay men together, trans people)
In the big cities at least, 'Pride' is largely commercialised and no longer exclusive to 'the gay community' - compare & contrast with Notting Hill Carnival, the commercialisation of St Patrick's Day.
The 'gay pride' (rainbow) flag is an import from the USA - I remember people wearing relatively discreet pink / black triangle badges in the 80s, but don't remember venues making themselves that obvious.
I'd say that the 'gay community' is more fragmented than it was 25 years ago - there isn't the same level of perceived threat (e.g. overtly homophobic government, AIDS) there was in the late 80s, so less standing together against those threats.
It is also now possible to be connected to others online - whether that's social groups, web forums, safer sex information, or shag-seeking, hence a relative decline in community newspapers / magazines / spaces and bars etc.
And what remains of the commercial scene is (again, certainly in the larger cities) more niche now - there are venues catering mainly for the disco dollies, venues catering for the 'bears' and so on, rather than what may have been an artificial solidarity brought about by a need for those local 'safe spaces' in the past.
There's also more 'assimilation' - arguably less need for 'safe space' (or self-imposed ghetto, depending on your viewpoint), and it is easier for gay people to aspire to / live in the mainstream - gay couples can do the barratland, ford mondeo, 2.4 labradors (or even children), 'professional' job, tory voting lifestyle and go out to mainstream places.
Whether this truly represents progress is questionable, especially when you get into the realms of the self defining 'straight acting' types who look down on 'those gays' who still do anything political or argue that we haven't yet reached utopia...
What was the question again?