A logical assumption would be that VT continue uses Cassell until the new arena is built somewhere on campus.

At least it wouldn't be reasonable to assume that VT would tear down Cassell to build the new arena in that location because it would probably require tearing down Jamerson Athletic Center and Merryman too. Too many people would be displaced from those 3 buildings and I don't think VT has enough offices available to house those displaced employees until the new building(s) are built. At least VT built the Surge Space Building in 2007 to provide temporary housing for displaced academic or administrative units while renovations are being done to their home building. However, VT designed the building to be disassembled and recycled in 10-15 years, so it may not be large enough or even available to the displaced Athletic Department employees.