What is Let You Go?
1.
I want to get off the phone now because I hate talking to you, but I'll pretend that I'm being polite by letting you go back to whatever boring crap you would be doing if you weren't talking to me.
Them: So then he said it was benign but I should probably get it removed. And I said-
You: Wow! That's nuts! Hey look, I'm sure you've got a lot of stuff to take care of. I'm gonna let you go. Bye.
Them: Oh, uh, yeah. Bye.
See
2.
~ Compulsory Redundancy
Sometimes alternative to "You're fired!", "You're sacked!"
Some would say it's a nicer more civil way of saying it. But really it's only of benefit to the person saying it.
Manager: Look Bill I've done everything I can but they just won't change their minds...
...I'm afraid we're going to have to let you go.
Bill: You mean I'm fired?
Manager: Oh dear no! Thats not what I said...
...but yes, you will no longer work for us.
See