Wikipedia states that Ito was the first to land the Axel in combination in 1988, though it doesn't say where...
Who knows, maybe Mirai will land a 3A in competition. I saw her attempting some at the rink today, and they're awesome! They're about half cheated, but she's landing on one foot and they're super high.
I think Yuna absolutely did push the technical side of figure skating, just not in the same way people before her did. While she didn't have the seven triples of Michelle Kwan/Irina Slutskaya (the two dominant skaters of the previous era), she had a 3-3 that was more consistent than Slutskaya's, more difficult than Kwan's, and better quality than either (Irina had huge height but wonky landings, Michelle had beautiful landings but not very impressive height, Yuna had both).
While Mao was more ambitious, I'd argue Yuna had a bigger impact, since many people are going for 3Lz-3T these days, and she is largely responsible. Granted, the reason women don't go for 3A isn't because they don't want to--it's because they can't. The reward isn't high enough, and the failure too costly, for it to be worth it.
With Yuna's 3Lz-3T and Mao's 3A, they essentially brought back the Kristi Yamaguchi-Midori Ito era (and interesting enough, like Yuna, Kristi was missing one triple jump).
Would I want to give Yuna a loop and a 7-triple LP? Of course! I'm sure Yuna would like that too. But I'd rather not seeing her going for the loop if she's going to fall on it most of the time, or if it'll lead to constant injuries. She deserved all her wins so I don't see what's the problem (scores circa. 2010 were ridiculous, but that's the judging system's problem, not Yuna's).
According to Harding's bio on Wiki:
At the Fall 1991 Skate America, Harding recorded three more firsts:
The first woman to complete a triple axel in the short program;
The first woman to successfully execute two triple axels in a single competition;
The first ever to complete a triple axel combination with the double toe loop.
So she was the first to do it in combo with A double toe loop is how I read that. What jump was Ito's 3A in combination with?
In reading Ito's bio, the only mention I can find of her doing the 3a in combination was one done in a practice session before a competition and that was a 3/3. A citation is requested by wiki for that. Ito had many firsts----first lady to do a 7 triple program, first to do a 3a at the Olympics.
At the 1991 Grand Prix International de Paris – a pre-Olympic event in Albertville – Ito beat Kristi Yamaguchi by completing a triple axel and five other triple jumps in her free skate. During the warm-up before the free skate, she landed a triple Axel/triple toe loop jump combination, which has still not been equaled by any other female skater.