I noticed new buds on my spruce since spring is starting. Could that be a sign of recovery since it was heavily pruned? And would that mean rewiring is acceptable?

Well, yes, it's a good response...

I wouldn't say it's time for a new wires if it was just repotted for example.
But if hard prunned, maybe I would wire the branches that are getting too stiff, new buds are fragile and you can end up damaging some of them.

I've always read that the best time to wire deciduous trees is on winter, and they shed the leaves and doesn't thicken much (reducing the risk of the wire bite in).

Wiring on the growing season requires much more attention.

When did you do the hardprune? Are we talking about a spruce bought during chrismas?

New buds appearing means there is surplus energy. So its a good thing, will give you more pruning options later in the season.
But if you pruned it this year, then the tree is still weak, as it had still have not had a summer to get some good growth to recover.

Albas wrote:

I've always read that the best time to wire deciduous trees is on winter, and they shed the leaves and doesn't thicken much (reducing the risk of the wire bite in).
Wiring on the growing season requires much more attention.

It's not a deciduous tree.
It does take a lot more attention, but i feel the need to wire during spring and summer, otherwise some decduous tree's have tickend up so much i am unable to bend them anymore at the next winter. So i need to wire the new growth when it is still flexible, and that is during the summer.

Rorror wrote:

It's not a deciduous tree.

Oh, I jumped the "spruce" when reading it.

Rorror wrote:

So i need to wire the new growth when it is still flexible, and that is during the summer.

Sure, like I said, I would do it if it's getting too stiff, only being more carefull about biting in.