I have a bunch of Sentry projects that I’d like to use as sources in Airbyte. So, that’s going to be n Sentry projects. How should I think about the destination in Snowflake? Should I create a new schema for each source? If I have n Sentry projects, n Airbyte sources, then should I have n Airbyte destinations where each destination is a different schema in the Snowflake database?

No you can re-use the Snowflake destination (have only one) and use Custom Namespace to send to a specific schema or use prefix tables to send all sentry to same schema but in different tables