33 percent of acquired workers leave in the first year

“A new study finds 33 percent of acquired workers leave in the first year of their startup’s purchase.” https://mitsloan.mit.edu/ideas-made-to-matter/your-acquired-hires-are-leaving-heres-why
How is your company dealing with the employee retention problem? I personally, experienced several times when PMI projects were restarted because the target’s key employees responsible for integration simply left the company.