Actually, they were depicted as romantically involved right from the start. There was a lot more censorship going on back in the day, but the creators pushed as many hints as they could get away with; those comic pages at the bottom of the article come from the original creators of the character, for example. And it…

Can’t two girls just be close freinds. Just like a boy and a girl can be close friends and NOT be dating.

It always been canon since the turn of this century. Even Harley creator Paul Dini and Bruce Timm already acknowledged Ivy and Harley type of relationship more than a decade ago.

“Can’t two girls just be close freinds” I hate this one. Two things about that: 1) Medias needs far more non-heteronormative representation that it needs friendships.

They’ve been hinted at as being into each other for a long, long time. This is just the first time it was actually confirmed (at least for this series).