That pretty much means you're in, just need a vacancy to come up
This happened to a lot of people a year ago, particularly with male applicants, as EK was trying to get more females trained first.
Not much can go wrong from here. I know someone who got that email twice (i.e. three months came up, and STILL no vacancy, so they sent him the exact same email AGAIN). He eventually had to go back for a short FI and he eventually got his call. This was very rare though...99% of people that got this email simply had to wait a bit longer for the call.
CONGRATS!!!