Over a conflict, an aggressive conversation occurred between the engineering manager towards the business lead. From the point of experience, there are ten years more on the side of the BL. Everything happened over Slack over the weekend.
Due to this, today, the entire engineering team had a 1-1 to skip meeting with HR to give our statements about the issue.
What usually happens after this meeting?
If the relationship between the Business Lead and Eng Manager is untenable, one of them will be transitioned off the project. This may cause churn in the project, so you should be prepared to fill in the gaps.
As an engineer, there's really no benefit to you here. It's not fun to be on a team where people are mean to each other, and this issue can have meaningful negative consequences for getting your feature or product to ship on time.
My recommendation is to minimize the amount of time you spend with HR and give politically correct answers. In most situations, it's not worth your time or energy trying to get too involved or "fix" the situation. If you don't see a path to this getting better, just switch teams.