The director for the department of the business I work in has resigned and left at short notice. As a manager, any risks with employees on my team leaving I feel I should flag, as a given, to the business owner, who is currently standing in for the director. However, I know that some of my peers are going to leave too, some of which I know would be unexpected to the owner, as they've weathered many difficult transitions before and are somewhat critical to the business.
I'm not sure if I should flag the risks of the other managers leaving to the owner, and if I should, how best to approach it. Without the director in place, I fear that the risks associated with the current situation or their departure may not be as visible as they should be and the knowledge and skills they possess will cause significant disruption to the business. I don't want to talk out of turn, but given that I'm not looking to leave, I would prefer to have some contingency planning in place to ensure any disruption from their departure is minimized...
Edit: Given some comments have not understood what I'm asking:
Should I tell the owner there is a risk of the other managers leaving and why, as well as highlight the risks that we will attract as a result? I've considered other "top" answers to similar questions and the consensus is generally "That's your managers problem, let them manage it" - My manager/director has left so the owner may be unaware of this risk and the impact it has on the business.
The other managers reasons for leaving are as a result of multiple iterations of restructuring the department and changing approaches to delivery, and feeling like we're not moving forward as a department. In attempts to improve department performance, there has been a restructure every 2 years, with previous methodologies and planning being thrown out each time.