Great to hear a non-disruptive upgrade fix has has been made available for this issue.
The issue is addressed in EMC KB175619
Essentially after approximately 80 Days of runtime the system may experience an unscheduled reboot. There is a workaround available which details how to perform a scheduled reboot of the SP’s 30 minutes apart. But more importantly an upgrade bundle is now available which fixes this issue: VNX BLOCK OE Bundle 05.33.000.5.038
Realease notes for OE Bundle 05.33.000.5.038: