Do my MYW tickets get linked to MDE when I buy them or do I have to wait for vouchers to arrive?

Do I have to wait for a voucher to link my MYW tickets purchased online through disney or are they linked to MDE automatically?

If you get then online through Disney while signed into mde they should automatically link immediately.

If you purchased a package from Disney it should be linked as well ( on line or call in). Look at your MDE information and you should see your tickets. If not, enter your confirmation number.