As it mentions already, it’s just an informational message. You don’t need to worry about rejection because of this.
What it means is that it cannot do API analysis before upload. It does this analysis to check if you use any restricted API’s from the SDK. So it could warn you and allow you to fix it before uploading. Since it’s too large, you will get the warnings (if any) about API usage by email within half an hour or so after submission since the analysis will be done on the Apple servers.