Are you accepting Xbox Party Chat invites? Malicious players can get your IP address (even if you are using a VPN) when you use the Xbox Party Chat function. This is the ONLY cause for having “personal DDoS attacks” in Overwatch and has nothing to do with the Blizzard servers themselves. North American servers have NOT changed at all. Its unfortunate, but this is entirely a Microsoft/Xbox Live problem. Remember you can work around this problem by changing your IP address for your router (ask your ISP for help with this), and then avoid accepting any and all Party Chat requests from anyone who do not know personally. Note that using the in-game voice comm channel does not expose your IP address to other players.
More details from Blizzard about this issue can be found here: