I fully agree with Clara - it is unlikely that your offer is taken back.
Needless to say, we are currently in a global situation of uncertainty and political actions (see Italy) like not having been since long long time ago. It will definitely have an impact on consulting industry since some consulting projects and budgets are temporarily already frozen - people sitting a bit on the sideline to observe what is going on. However, once the uncertainty is going away, typically consulting projects are taking up speed again - think specifically about cost cutting and reorganizations. And for that, consulting firms also want to be prepared human-resource-wise.
In addition, it's a small industry and rumors easily go around - and it doesn't sound good within the industry, and even worse for the image for future applicants. So if it's reasonably possible to avoid, they will avoid cancelling issued offers!
Hope that helps - if so, please give it a thumbs-up with the green upvote button below!