iTunes Match enables you to play your music from the cloud on all devices. If you are no longer paying for this, then you no longer have this service on the other devices. That means any songs not downloaded to a specific device while iTunes Match was active will not be playable and will appear grayed out.
Your Music library however should still exist on the computer from which it was matched for iTunes Match originally and be playable. i.e iTunes Match scans a library that exists on a computer to make it available to other devices. This library, unless deleted by you should remain on the computer from where it was matched. You can manually sync this library to any device including your iPad using the USB cable.
Sync your iPhone, iPad, or iPod touch with iTunes on your computer using USB - Apple Support
iTunes Match is a separate service to Apple Music. While they work the same way for matching music. Having used iTunes Match does not automatically mean your music is available through Apple Music less so if you are not paying Apple Music
Apple Music is a service, like iTunes Match. If you want to keep using its benefits like accessing music from the cloud on any device you need to keep paying for it.
With that said, you don't sync Music to iTunes. You add or import Music from CDs to your iTunes Library on a computer. Your library can then be Matched with iTunes Match so you get access to copies of that music from the cloud on any device.
You can, if you do not wish to use iTunes Match, sync music via USB cable to an iPad, iPhone or iPod.