That should work fine. The purpose of the Migration Assistant is to identify things can potentially could be an issue in the migration.
One word of caution though: before you restore the database, make sure that you have applied the most recent Cumulative Update to SQL 2019 which CU13.
Keep in mind that when you restore the database, it will remain in compatibiliy level 140. You may want to do.
ALTER DATABASE db SET COMPATIBILITY_LEVEL = 150
to get access optimizer enhancements in SQL 2019. Although, there is a small risk that the enhancements may backfire.
The one which is likely to have the biggest impact is inlining of scalar UDFs. There were a couple of issues with this change which have been addressed in a couple of CUs. That's why you should make sure that you have CU13 installed before you restore the database.