This is the sort of thing that can change that. Any holiday pay or extras that may have been owed to this employee might disappear, they could also have been fired immediately if twitter wanted to send a message and acted fast enough.
No matter how much they might be angry about it, they're not going to withhold money they legally owe to the employee. And besides, the check has already been printed at that point, and may have already been in the employee's hands, since many places legally require any back pay or unused vacation to be paid out on the final day and no later. Employers who try to screw with that typically only do so because they don't have lawyers or HR departments, and quickly learn why those are useful things for an employer to have.
can you imagine the scale of shit storm that twitter will be hit with in this scenario? This individual is called "THE legend"[1], people praise him/her [2], [3].
not sure what extras you're thinking about but if it's something like payout for unused vacations they can't take that away from you even if they had fired the employee.
read the comment I replied to https://news.ycombinator.com/item?id=15617061 he offered $10 to the next employee. My guess is that anyone who disables Trump's account because they can will be fired.