I do not kn ow the details of this particular situation, but I have signed agreements myself (or my business has), in both directions, that has a very standard "separation" clause that requires each side to be available to each other, sometimes for unspecified, lengths of time. Usually the reasons are spelled out, and also usually apply to legal matters such as law suits or other legal disputes. And sometimes there are, quite reasonably, no time limits (i.e. a legal dispute connected to the work done by the company or ex-employee could arise years after the separation), and even when time limits are spelled out they are usually for much longer than the so-called time covered by a severance payment.
Jelly -- I assume that the agreements you've been involved in are at more senior levels of the organization. I think this type of open-ended availability is pretty unusual at lower levels of the organization. Is there any legitimate reason the SunTrust Banks needs to include the clause in the separation agreements for 100 IT professionals to make themselves available for 2 years regarding any matter in which they've been involved over the course of their employment? If there is a pending legal matter, then SunTrust should specify that in only the separation agreements for the handful of employees who reasonably would be called.