I am also freelancer and I have done some research on GST and concluded that registration is not required.
As per CGST Law section 23 (1) page no. 25 in the PDF file,
23. (1) The following persons shall not be liable to registration, namely:––
(a) any person engaged exclusively in the business of supplying goods or services or both that are not liable to tax or wholly exempt from tax under this Act or under the Integrated Goods and Services Tax Act;
So, if you are a freelance service provider or Proprietor with some employees and if you are doing services only to foreign customers (no Indian customers), then as per the above CGST rule, it is not mandatory to register under GST. Because, as per IGST law Chapter VII 16 (1), export of services will be zero rated supply which means that export of services are NOT liable to service tax. So, as per the above rule, GST registration is not mandatory.
If you need to claim Input Tax credit, then only you need to worry about registering under GST. For freelancers the input tax will be very less. Typically, only the Internet bill will have some service tax paid. If you purchase any computer, then we pay service tax. If you are not willing to claim these input tax, then GST registration is not mandatory for freelancers servicing only foreign customers.
I appreciate your inputs on these points.