Getting back to what Trump actually admitted:
"in no circumstances, you're promising America tonight, you would never abuse power as retribution against anybody."
Trump is admitting he would abuse his power as president. He would exact retribution (which is different than undoing a policy)...

Snip
“You are promising America tonight you would never abuse power as retribution?' Hannity asked the former president, who is leading President Joe Biden in a series of polls.

'Except for Day One,' Trump answered.

'Meaning?' Hannity asked him.

'I want to close the border and I want to drill, drill, drill.'

'That's not retribution,' Hannity pointed out.

Then Trump tried to get a laugh out of the line.

'He says: You're not going to be a dictator. I said "no, no, no – other than Day One. We're closing the border. And we're drilling, drilling, drilling. After that I'm not a dictator.'

A Biden-Harris account tweeted out the clip, appending the line, 'Trump: I will be a dictator on day one.'”

dailymail.co.uk - Donald Trump REFUSES rule DICTATOR Tells Sean Hannity revenge enemies Day One dodging question abusing law peo


And LOL....
“The Biden campaign made hay out of Trump's comments about 'Day One'”