The existing (legacy) Asset Hub lane will continue to function just as before. Once we have the Permissionless dedicated bridge lanes deployed live on both Polkadot and Kusama chains, we can switch over the Asset Hub lane traffic from the legacy lane to the new one with practically no downtime.
Support for Permissionless dedicated bridge lanes #476 will be deployed on Asset Hub instead of Bridge Hub as explained here.
The existing (legacy) Asset Hub lane will continue to function just as before. Once we have the Permissionless dedicated bridge lanes deployed live on both Polkadot and Kusama chains, we can switch over the Asset Hub lane traffic from the legacy lane to the new one with practically no downtime.
Some more details here.