I can hit F2 to edit the text, as normal, but it will not display. On other downloaded shapes/stencils, if I right-clicked on the shape/stencil, I would have the option to hide/show shape text, but it doesn't exist on this one. I have looked in the shapesheet data, and "hide text" is already set to false. In developer options, the text is not protected.
In my role as an Advisory Solutions Architect I create a good bit of documents for internal and external customers. Today I am working on an Avamar and Data Domain solution. EMC is fairly good at providing Visio stencils. A bit more for their core (VNX/VMAX) products then for some of their other products.
Emc Vnx Visio Stencils