Why is it disappointing? Didn't you pack it yourself? Norwegians make the matpakke they want to eat. (Source: Am Norwegian.)
Would colleagues be offended in any way if your dish was particularly aromatic once reheated?
Most people don't bring leftovers, though. They typically pack open sandwiches that they make themselves.
A lot of companies have kitchen areas that they keep stocked. People typically make sandwiches (open, again!) and salads. I've never seen anyone hear anything in a microwave.