Here's why it's highly unlikely Blaze the Cat would be in a hypothetical "Sonic Heroes 2":
* Sonic Heroes 2 is not confirmed: As mentioned, there's no official announcement of a sequel to Sonic Heroes.
* Blaze's role: Blaze is primarily associated with the "Sonic Rush" series and its spin-offs. While she has appeared in other Sonic games, her connection to the "Sonic Heroes" style of gameplay is not as strong.
* Team composition: Sonic Heroes' team-based gameplay focuses on specific character combinations, and Blaze's powers might not fit seamlessly into the existing teams.
In conclusion: It's purely speculation to say whether Blaze would be in a potential "Sonic Heroes 2." Until there's an official announcement, it's best to wait and see what the future holds for the Sonic franchise.