Overall I agree with Chiron's response but I would be curious to see exactly what Fannie Mae sent over in their "request" ... such as an authorization form that had previously been signed by you as part of the original mortgage application or closing paperwork.
As a side note, it would be interesting to see what would happen in this scenario if you no longer worked there (especially if you already FIRE'd).
Realistically they should only verify employment as of six months ago. A *new* verification of employment seems kinda shady to me ... like what are they going to do if they don't get it, call your loan by activating the acceleration clause? Otherwise they'll just have to suck it up and cross their fingers that they got a quality loan. (Due diligence, anyone?)