Auth0 Legacy Lock API Deprecation

Question

I went through the Legacy Lock API Deprecation documentation provided link

I have few clarifications

Its mentioned that by July 16, 2018 deprecated services will be removed.

And the criteria are given to identify whether I will get affected or not, below listed

• Use of /usernamepassword/login endpoint directly from applications
• Use of /user/ssodata endpoint directly from applications

In my application I have integrated auth0-js and I been using auth0.redirect.loginWithCredentials() function to send the username and password along with connection (database connection).

This function actually calls co/authenticate REST end-point.Does my current implementation needs a migration, will I be affected by services that will be stopped by Jul 16.

Another question: In the advanced settings of a tenant, its advised to disable the Legacy Lock API option under Migrations (see below image). If I do so I get pre-flighted error which is a CORS issue, any relation between this problem and previous question or how do I solve this issue