Draws due to e.g. server issues should not affect ELO (or whatever rating system is used behind the scenes)
I was attempting to play a ranked historic match and after waiting a while (~ 1 minute, I was doing something else while waiting so I don't know the exact time), matchmaking ended, I was paired against another player, and the match immediately ended in a draw.
However, when loading the next match I noticed that my Mythic ranking had dropped by over 20 places. As the player I was paired with had a lower ranking, the most logical explanation for the discrepancy is that the server-induced draw had affected the ratings of the players involved in the match the same way that a drawn game caused by user actions would have been rated.
Ending the game prior to any user input is a fine response when some error in either the server, a client, or network prevents an assigned match from starting properly. However, games that are ended in such a manner ought to be treated as though no game was played rather than as a draw for rating purposes.
If it helps investigate, I've attached the log file from my play this morning. The drawn game should be the second-to-last one played.