They made the TL that way on purpose then just renamed them top make more money. It is the same thing they did with the Shark as the Champion plastic would not dome up for the old Champion Sharks, look at one of those online. The old champion Sharks are a 3 that is made now.
This is a good point that you bring up. Conspiracy theories aside, I feel like when people argue over the differences between 3series molds vs originals, that it's kind of in their heads a bit. I have flat versions of eagles, teebirds, TLs, and leopards that could all pass for 3's. They all happen to be older plastic, but I think the variation has always been there between runs, or whatever. Do I think my flat teebirds are a speed faster and have less glide? No. That part feels like marketing to me. But I do think it's good that consumers can now order a 3 and expect it to be "flatter" than the original mold. I remember back in the day when people would flat top their rocs for whatever reason. Now I guess no one has to do that.