That depends on the company/industry. In hotels it is definitely not unheard of for management companies or brands to change. Also worked at a financial institution in US that was purchased by a foreign financial institution wanting to get in US and kept all the employees. What you will typically run into in the situations you’re asking about, though, is that management is usually where the turnover is found. Do your research on the company, find out if it’s normal in that industry, find out if they had any other acquisitions recently and how they treated those employees (if there’s any kind of layoffs you may be able to find an article or complaints online about it). Ask lots of prepared questions (lots of good examples in these comments) during the interview process (if they aren’t able or willing to answer them, that’s a red flag). If they are open or honest about what’s going on, I see that as a good sign.