Or because they outright made his origin impossible by gender bending his father and killing her off in the 1990s (Captain Marvel was a period piece set 30 years ago). A comic accurate Mar-Vell would've been male and died in the 2010s, making it possible for a teenage Hulkling to exist. Thanks to what they did though, he'd need his parentage changing, else he'd be too old.
There is maybe one advantage though. If Skaar becomes MCU Hulkling you can bet he'll take the role in the comics too, which means Teddy would probably get a new and more fitting name. After all, Skaar is actually a Hulk, unlike Teddy.