Without proof, my best guess is this move has to do with the massive investment Linden Lab made in Project Sansar in light of greater-than-expected competition and less-than-expected positive reviews and interest from customers.
Hamlet Au suggests this may be a move to develop Sansar as a gaming platform or engine (similar to Unreal but for VR) not a bad strategy, although Unreal is developing their own VR application.
Linden Lab is also advertising for a new director of Human Resources
No word on who this replaces or why.
Linden Lab used to be known for its relative employment stability among Tech companies, but lately that seems to no longer be true.