Too soon - just look at some of the other threads on him around here. Also need to see if he stays out or lands a gig somewhere else.
Need to make sure he'll get a good reception. To do that: (1) wait until we're more definitively back on track and likely to be having a good season so the crowd is in a good mood; (2) honor one of his teams on an anniversary of a special season or something and introduce him (whether or not he actually attends) along with the group to gauge the response; (2a) could also have an event honoring all past coaches, but that could get awkward due to some of the more recent ones ; and (3) if we're at a point where the nostalgia outweighs the bitterness, bring him in for an individual honor.