Can a new plan provide for full vesting on a change in control?

Do you know of a reason why it couldn't?

No, with so many changes these days, however, I just wanted to be sure that I was not overlooking something.

If a plan provides for full payment at vesting and the CIC accelerates vesting, it could be that you have a non-qualifying, event based distribution. However, since the payment would happen within the same tax year as vesting, I don't think it would be a deferred compensation plan (for the affected participant) so I think it is still OK.

I have listened to several webcasts and teleconferences taking the position that event based accelerations of vesting are permissible so long as the distribution events are limited to the permitted list.