Message transfer to new iPad.

We don’t know if “previous messages” means iMessages or SMS messages.

What is the difference between iMessage and SMS/MMS? - Apple Support

We don’t know what “synced with iCloud” means. Some possibilities:

• Restored a backup from iCloud
• Use iCloud Messages
• Signed on to the new device using the same Apple ID as the old device

iOS 16 introduced iCloud for Messages.

Keep your messages up to date with iCloud - Apple Support

Now that messages may be stored in iCloud, they are no longer contained in iOS backups as they were prior to iOS 16.

Backup methods for iPhone, iPad, and iPod touch - Apple Support

If you didn’t choose iCloud for Messages, they are not available for a new device.

If you have an iPhone - and both iPad and iPhone are signed-in to iCloud with the same AppleID - to send SMS/MMS messages (green bubbles) from your iPad you must explicitly enable Text Message Forwarding for your iPad on your iPhone...

On your iPhone:

Settings > Messages > Text Message Forwarding - set to ON - and explicitly enable your iPad from the list of devices.

Also ensure that Messages in iCloud is enabled on both your iPhone and iPad:

Settings > [Your Name / AppleID] > Messages - set to ON

If you still have your old iPad, if the messages are still present, you simply need to ensure that all devices are signed-in to iCloud with the same AppleID - and that you have enabled iCloud Messages, as described, on all devices.

Here’s general information. It may not address your specific need.

Manage and delete contacts on your iPhone or iPad - Apple Support

Unless Messages from your old iPad and your iPhone were previously synchronised with iCloud Messages, your new iPad will have no Messages to retrieve (and synchronise) from iCloud.