I think the claimed conflict is fundamental, not coincidental. When people talk about employee board representation, the central example of the representative they're talking about is someone paid to be involved in day-to-day, on-the-ground operations. Someone on the board of a large company would be worse than useless without dedicating a decent amount of time with understanding the complexities of the company's operation, which means they won't have time to be spending on the factory floor (or whatever) like a regular Joe.

This isn't insurmountable, as none of these constraints are inherent to the concept of employee representation. But it does require some more detail, or you end up with a decidedly non-central case like the one described elsethread, where Sundar Pichai counts as employee representation.