I think the bigger risk is you write a blog about some "cool stuff" you are doing and it's actually not cool, it's dumb and obsolete and people who might have been thinking about working at your company go apply to Microsoft instead. There's abundant examples of "How we handled a billion queries per year with only 1000 servers" out there. It's the risk that you don't know how you really compare to your peers.

Personally, the only "technical blog" I want to see from a company is papers accepted by OSDI, ISCA, VDLB, etc.