@sakuraime Azure Database for MySQL has been developed from MySQL Community Edition, using the InnoDB engine.
Migration shouldn't be an issue if you are running MySQL 5.6, MySQL 5.7 or MySQL 8.0 on prem.
From a support perspective, Microsoft provides automatic minor version upgrades and offers major version upgrades as a choice for customers.
You can get more details here
Please let us know if you need further information.