Why would you want to take back what you've said? The ability to purge history removes the cost of being caught out in deception.

I have expressed myself poorly on the past. I have regretted the way in which I expressed myself.

Accepting that I cannot change this past expression pushes me to express myself more honestly & carefully.

Speech should be free, but you also should be held accountable for your expression. You should hold yourself accountable for your expression & move forward with intention.

Speech is a cheap form of action & I think adding some cost to it is beneficial in the quest for greater Truth.