I can answer and tell you a few things planned so far ^^ not an issue.
1. Some of the main cast might show up, but most of the cast is planned right now to be new characters with new stories.
2. If Corsica does appear in the next game, it's assumed the good ending is the cannon ending and Corsica's design will be altered a bit from the drug use.
3. The sequel will happen directly after the first game, with the same player as the first game, however it will be in a different location with a different city and story.
Hope that satisfies your curiosity ^^