Blue and Gold are not "steeped in nostalgia." When I read Action Comics, it's a pure '90s throwback. And Green Arrow is just watered down Mike Grell. If that's what people who enjoy them like, great. But even though they're new, I feel like I've already read those books in one form or another so my interest is limited.
Blue or Gold are their own things. Blue isn't just the '60s X-Men all over again. And Gold isn't just a Claremontian flashback.
Acknowledging and incorporating history isn't nostalgia. And solo books like Jean Grey, Iceman, and Cable certainly aren't nostalgia trips, either.