There is some confusion about durability of data stored in SQL Server in-memory tables, so some review of the concepts is appropriate. The in-memory option is enabled at the database level. Enabling it at the database level only gives you the option to specify the in-memory feature on a table by table basis. No existing tables or new tables will by default become in-memory tables when you enable the feature at the database level.
If you choose to make a table an in-memory table, by default it is durable with changes being recorded in the transaction log. You do not have to worry about data loss. However, you have an additional option of making an in-memory table not durable. If you actively choose to do this, you will have data loss if, for example, the server crashes. There are legitimate use cases of choosing to override the default behavior and create in-memory tables that are not durable. If you need staging tables for ETL, non-durable in-memory tables will provide high performance. If you need temporary tables for a particular processing need, non-durable in-memory tables can outperform tables in tempdb.