Yes, it definitely is a trend and it's great. There is a direct correlation between the decline (well, more like collapse of the once all-powerful RC church) and the societal acceptance of LGBT people. An openly gay Taoiseach would have been utterly unimaginable even 15 years or less ago, but the (IMO rightful) scorn on Varadkar and his cabinet, at least in the media and body politic, focus on his policies and actions and not who he goes to bed with.
And my facebook page is full of happy images of same-sex marriages. Only thing is that it makes me a bit envious/sad as I'm still very much single at the moment.
That said, there is still a sizable rump of homophobia, particularly among older males and in rural areas. Let's not forget that over 37% of those who voted in the 2015 SSM referendum voted against same sex marriage. It's easy to be lulled into a sense of complacency if one lives their daily lives in hip and trendy Dublin districts.
When I first joined the Gaire message boards in 2004, there were so many regular posters still deeply in the closet and those who were out were often at the receiving end of homophobic abuse and rejection by their families and friends. There were posters on here whowere agonising about coming out to their families and friends who are now happily married to their same-sex partners with their families and friends celebrating their unions.
That's real progress in the space of less than 15 years.
But let's not think all is rosy for LGBT people in Ireland now. Our brethren up North still can't marry, face huge bigotry and hatred from much of the loyalist/DUP/ religious headcases (often one and the same) and island-wide homophobic bullying in schools and some workplaces is still a big problem. Also, societal acceptance of Transgender individuals still is in its infancy - sort of where it was for lesbian and gay people about 25 years ago. We cannot be too complacent. There is still a way to go.
IMO homophobia, like racism, sexism and other forms of bigotry will never be completely eradicated but it can be kept in check if society deems it to be unacceptable.