For Jovian and Saturnine moons, the simplest answer is no, at least not much more habitable than our own Moon is, because none of these moons have their own magnetic field or sufficient mass and their atmosphere would eventually thin out via the ionospheric hydrogen loss due to the solar wind. A bit more difficult answer is how many of these moons would be well within the parent planet's own magnetic field and still sufficiently protected from solar winds and cosmic radiation to sustain a breathable atmosphere, liquid water, and life as we know it.
Being within the goldilocks zone also means that these celestials would orbit well within the star's snow line, so their surfaces would form completely differently than they indeed have in the outer Solar system, past the snow line. They wouldn't acrete as much of water ice as they did, and the liquid water would be more exposed to escaping hydrogen (hydrogen atoms aren't really strongly bound to oxygen atoms in water molecules, and UV radiation in upper Earth's atmosphere is sufficient to produce extremely light hydrogen ions that move to ionosphere).
So it's difficult to say how such moons would even look like. Would they be barren rocks? Or could they hold onto enough water and sustain a breathable atmosphere? Would they even form at all from the protoplanetary disk, or would we mostly see captured planetesimals orbiting goldilocks Jupiters? I'm not sure that anyone can even answer these questions, there's enough of discussion even over our own Solar system's formation, but I'm fairly confident that there's not much point in discussing if Titan, Enceladus, Europa and alike moons of Jupiter and Saturn could support own, water-based lifeforms or be suitable for human colonisation, unless we can establish with a fair degree of certainty that they could even exist. For all we know, it might not be possible for them to hold onto so much water as some of the Jovian and Saturnine moons do. So it's quite possible we'd see much smaller, rocky moons and moonlets, with even smaller mass and surface gravity than we currently do.
But I'm not going to say it's impossible. Jupiter has incredibly strong magnetic field, likely sustained by the metallic hydrogen within its core, and is large enough to stretch nearly to other neighbouring planets. But how all this hydrogen actually moves in protoplanetary disks as their stars evolve, increase their temperature and push the snow line and blow lighter particles away, while at the same time consume a great deal of hydrogen to sustain their nuclear fusion, is still a bit of a mystery, as is the source of all the Earth's water. Perhaps we gained most of it via Late Heavy Bombardment of icy asteroids as the Earth's surface started to solidify? So what I'm saying is, that if such Jupiters form closer to their parent star, and within the goldilocks zone, we don't really know if they'd even be able to sustain a strong enough magnetic field. Composition of their inner cores might be entirely different than of our Jupiter. Even other gas giants (which leaves Saturn really, because Uranus and Neptune are ice giants) in our own Solar system don't support such strong magnetic field as Jupiter.
Anyway, these are just some thoughts on the subject, and why I think it's too speculative and we lack sufficient understanding of even our own Solar system's formation, to transpose this knowledge onto exoplanets we know even less about. I guess the proof of the pudding will have to be in the eating. I.e. we'll know, when we detect some.
