They are still producing the replacement battery for the Move. It is probably just out of stock in your country. It is currently in stock in the US.

I don’t think there are any Sonos Moves old enough to need a replacement battery pack yet. This is certainly the first post I’ve seen about the issue, ever. 

If you do see an ‘out of stock’ notice for a product on the Sonos website, there’s often an option that will allow you to be notified when it’s back in stock - so perhaps consider using that too, perhaps?

If you are considering the purchase of a spare battery now, in case you need one in the future, I don’t recommend this strategy because unused batteries, potentially sitting for years without being recharged, do not age well.

Thank you all for the infos