No there's no evidence to suggest that these two things are related. Reactivating the BCT is just cancelling that years-long process and all of a sudden they go from dissolving the unit to preparing for a deployment to Afghanistan.
It's a lot of people to deploy at once to a place where the news we read on a day-to-day basis doesn't seem to note the apparent need for them to be there.
Between Afghanistan and Iraq there are (officially) nearly 10,000 strictly military personnel deployed just in the US Army. The BCT deploying raises the Army's presence in Afghanistan by 25%.