Answer:
Definitely no. Not because he doesn’t deserve it. Not because the country needs a continuance of his policies. Not because of any justification. He shouldn’t get it for one simple, immutable reason: Change in the Constitution is so important, so fundamental to the nation, that any change must be done with cold reason, dispassion, uninvolvement. No one involved in the change should personally benefit as that will color their decision. It must be prospective only, applying to those in the future.
You don’t change a Constitution to suit a particular moment, you do it to set the foundation of a society. If the Constitution is changed to give this leader a longer term, then the next leader will get it too—and he or she may be a bad leader you can’t get rid of for now even longer.
A Constitution is the lifeblood of a nation, you don’t play around with it to suit a political moment.