Adding Guidance for managers to determine termination timing for involuntary offboardings

Why is this change being made?

We want managers to consider a transition plan when they schedule involuntary offboarding calls in collaboration with Team Member Relations. This should overcome the instance that any involuntary offboardings are scheduled during team members being on-call or scheduled for customer sensitive meetings.

In short the guidance we're providing is:

• Avoid scheduling a term while a team member is scheduled for any sensitive customer meetings or is on-call
• If this is unavoidable the manager should consider a transition/contingency plan before the offboarding call happens.

Context on slack conversation here.

@pegan @dcives-ext @atisdale For your review.

cc @gl-peoplepartners

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