Re: Visa Update
Probably checking things over with your employer....I'm not suggesting that it wasn't legit but sometimes they write to the employer to check the details provided, especially if your salary going into your bank account is paid in under a different name to the company you work for.
Or if they have doubts over the suitability of the accomadation you propose to live in, then they write to the council and ask them to confirm its availability and condition etc.
Don't worry about it too much, you should hear back soon Inshahallah.