When creating tables in Module/Setup/InstallSchema.php I would like "Magento\Framework\DB\Ddl\Table.php" to support the JSON data type as it has its advantages. For DBs that do not have a JSON data type, they can default to text.
At the moment I need to add my column manually to enable the usage of the JSON data type.
$sql = <<<EOT
ALTER TABLE my_table ADD COLUMN column_name JSON NOT NULL