Once established, hostas are pretty tough, as you've probably noticed if they've been in your front flower bed for years. They are high on the favorite snacks list for slugs, deer and rabbits but if critters were eating your plants last season you'd probably have noticed that. Or could the deer/rabbits have already trimmed off the new shoots?
Hostas are typically very winter hardy so unless you had a hard frost early last fall, before the plants slipped into dormancy, that probably isn't the reason the plants haven't emerged.
Is there any chance that Roundup or something similar might have been used nearby and blown over onto these plants? Almost sounds like a poison issue.