It's a bizarre excuse if real. Does this young man think GT - or ANY other program - is going to stop or slow down recruitment of defensive backs? I have never been one for the "wouldn't make our scout team" angle except when using for sarcastic attempts at humor of course or the like, but this young man probably isn't cut out for Tech. And, quite frankly, again assuming this is one of his primary reasons for discontinuing his desire for Tech, he is in for a world of hurt at ANY program if his specification is minimal to no recruiting at "his position" after he commits to wherever.
Best for both sides (especially us) and good luck to him. I can understand this more in hoops with far smaller rosters and fewer positions such as a point guard, btw. Or, perhaps at a specialized position like QB or PK or P even in FB where there is one position on the field. But DB's who play 5-6 positions and contribute heavily in special teams? No way.