2NLs are starting to be sent for December interviews (DV2019). I have only seen a couple of people saying they have received their 2NL, so it is likely that they are spreading out the 2NLs over time – possibly the whole remaining part of this month.
Some people previously got 2NL emails but then had to wait days or even a couple of weeks before the interview letter showed on the ESC page. Other people waited until the beginning of the following month to get their 2NLs and ESC page update. So – be patient, stay calm. Some physicians won’t schedule the medicals unless you have the 2NL in hand, BUT there is plenty of time before these interviews, no need to stress out!
The email itself has no useful information. It simply tells you to check the ESC site for the interview details. Some people that receive the email will find the ESC site is not ready, those people should try again after a few hours. Also, some people find the email itself goes to a trash or spam folder or somehow miss it. So – if you think you may have been scheduled but missed your email, you can check the ESC site, just in case. The 1NL (you have been selected letter) is replaced by a new letter which gives the appointment details.