While I can see how that might be a sensitive issue, I don’t think it would be a LEGAL violation.
The first Q is whether personal privacy laws even apply in a workplace setting. Alberta, BC and Quebec do provide employees statutory privacy rights; employees of federally regulated companies have equivalent rights under PIPEDA.
Assuming statutory workplace privacy protections do apply, the next Q would be whether information about job performance would be deemed protected personal information. While I haven’t researched it, my guess is that it would not fall into the category of protected information.
Another key Q is whether employees have a reasonable expectation of privacy in that information. The answer to that would turn on what your HR policies say–thus, for example, you could probably blow the argument out of the water by including a specific provision stating that info related to job information belongs to the organization and that employees should have no reasonable expectations that it will be kept private. Other factors would include what your employment contracts and collective agreements say or don’t say.
But having gone thru all this legal stuff, I’d also quickly add that this might be better addressed outside the law via old fashioned negotiation. Have you asked your employees if they’re upset’ If so, have you explored ways to allay their concerns’ Maybe you can work something out.