My wife's company was taken over by a new company earlier this year - some staff were let go and others temp laid off but now recalled. My wife's job was okay and no issues. However recently they have asked all employees to upload their current Cv - is that okay?? Just wanted to double check

The request to provide a CV is an internal matter at the discretion of the company and it is generally in your wife's best interest to comply. That said, if your wife transitioned from one company to the next without signing any employment contracts, her previous service would have to be recognized. So if they wanted to terminate her at this point, they would have to provide a severance package based on all years between both companies.