Check engine light after changing transmission?

So I got the transmission on my 2000 Honda Prelude (Boring Automatic )replaced. When I got it back, I drove it around for a while and the CEL came on. It doesn't really happen on the streets but ALWAYS comes once I hit high speed/freeways. I got it scanned and it pulled codes P0700 and P0740 (Fauly Circuit and Tranny Malfunction) The guy at the tranny shop said the CEL is going off because the torque converter hasn't worn in yet, so he said just keep resetting it. ( This gets annoying because it deleted all my radio stations every time I do this) So is the guy just BS'ing me or what? Because I've been resetting the CEL 2x everyday for a week.

Read more: Check engine light after changing transmission?