Disney is all about corporate synergy so it’s usually the case that introductions like this take place alongside new theatrical releases.
It makes one wonder why Doctor Strange didn’t debut in the fall of 2016, alongside his solo movie.
All it would have taken was a costume design so it’s not like there were any technical limitations.
While Disney doesn’t give a specific date for when Doctor Strange will be available for a meet and greet, it seems likely that he’ll be showing up some time in the next couple of weeks, very likely alongside the release of Avengers: Infinity War, which is the next time we’ll see the character on screen.