Rabbitwitch

Hi guys, I’m dealing with a similar problem in terms of school A and B where I need to make a decision for A by April 15th but B can’t let me know until after/does seem unlikely this year. I’m wondering if being upfront about preferring B over A will make them rescind my offer and if reneging is still possible/how bad it is in terms of bridge burning. Any advice would be helpful, thank you!