Not necessarily. I know an upper level dressage horse with a lameness that NO vet can solve. The latest vet suggested getting the chip in his pastern removed. The horse went to New Bolton for the procedure and is still lame.
If you are considering this horse, I would make sure to get all past vet records to see if this is an on-going lameness issue. I would also not make an offer on the horse until it is been back in work for some time and only if the horse has a clear vet check prior to purchase. You don't want to send your money on a horse that may not be sound.
The horse may or may not be able to do any serious jumping. There are sooo many variables with knee chips.
If you are serious about this horse I would get it vetted with full x-rays of the knees just to be sure. But then again that's alot of money to put into an OTTB when there are tons of horses out there off the track or not without past issues and priced fairly.
If it were me I would keep looking.