To be fair, even comic books themselves are no stranger to depicting relationships between younger men and older women. This happened before in Legion of Super-Heroes where this heroine Ayla Ranzz briefly hooks up with a younger hero. This also happened several times over in the X-Men stories especially with one heroine Rahne Sinclair being in hot water for dating a younger man. Then you have the centuries old Mystique going after younger men.
But I suspect this is going to be dwarfed by stories about younger women going after older men in some fashion or another. The younger Jean Grey sometimes falls for the older Wolverine. Rogue fell for Magneto. Kitty Pryde fell for Colossus, though it seems vague given their actual ages. Susan Storm married Reed Richards. Heather MacNeil fell for the older Vanguard. There are certainly superhero couples where the characters are in the same age group or so.
It would be rarer to have an older woman go for a younger man and successfully so. This isn’t to say that the likes of John Byrne are necessarily paedophiliac or ephebophiliac but that there’s often the feeling of wanting to be superior to an inferio character. But making the woman much older would turn this on its head. That’s if she’s also rich.
Supposing if most of the Justice League and their (surviving) colleagues are in their 1970s but with Patty Spivot (onetime officemate of Barry Allen) went after a man in his early twenties (in fact he’s even a Balinese gigolo) that it does upend or reverse the usual conventions in superhero comics and maybe the media in general.
Bear in mind it’s actually not uncommon for Western women to go after Balinese gigolos (or Ukrainian and Russian women to marry Korean and Chinese men) that it does make you wonder if Asian men could be desirable or interesting on some level. It’s also not uncommon for gigolos to go after older, richer women too.
The big problem’s that such a portrayal’s not just rare but in the case with Rahne Sinclair and Ayla Ranzz these are often very brief affairs. Or with both Rahne and Mystique, there’s a shady air to it. Patty Spivot’s another matter altogether but because she’s a supporting character and generally nothing shady about her.
At least up to that point should she be caught dead dating a much younger man (the age gap would be all the more significant if she were in her seventies) that would rock the superhero media world. But because it’s so unexpected of her that despite predecents, it’s a tad too controversial for many readers.
That’s not to say I condone May-December relationships but it seems a good number of superhero couples where the lovers are more or less their age or within their age group that it’s not a big stretch or so I think. (I hardly read comics these days.) As for 70-year-old Patty going after a 20-year old Balinese man, it does exist in reality.
But it’s already this rare for a woman to be into younger men, let alone without a shady air to it, that it’s probably why such relationships aren’t commonly portrayed. (I could be wrong but I hardly read comics these days so.)