Guys. You're jumping to conclusions on the helmet.
She's popular enough that she might be the only SDCC figure to get a retail release like last year. Hence the mostly part. She's popular enough for a limited release, not so much for a wide release.
While it's certainly not completely comparable, NECA's last "little girl" figure was Rue from the Hunger Games, who was exclusive to TRU. And while all the HG stuff generally made it to clearance, she was packed to the brim at TRU, orange stickers galore. People took the main characters first, the casual collector audience ignored Rue, even if, from my understanding, she's a beloved character or something.
Let's keep going.
Maybe she's in a two-pack for SDCC with a jacketed Ripley and the single carded one is the normal release. Or vice versa.
You people have to realize NECA is a business. This isn't a reused sculpt. This isn't a reusable sculpt. The helmet alone, admittedly, is not enticing enough as an exclusive (but maybe that's just me, seeing as everyone is getting their panties in a wad). They will not isolate this figure in its entirety to SDCC; they couldn't capitalize on the tooling costs that way. I also don't think they would advertise the helmet if that was the exclusive piece.
Remember thermal Dutch? Yeah that was a SDCC exclusive. The demand was so great for it that it was released as a standard figure. Have you noticed the elusiveness of the answers about SDCC? She could get the switcheroo and be a normal release after NECA gauges response.
When it's all said and done, she still is just a figure of a little kid; while the rest of us want her in the collection, remember that the average consumer will take an Alien or Ripley over Newt any day of the week. I can hear it now: "my TRU won't stock any new figures because the pegs are clogged with Newt, they need to clearance her out". Same thing happened with Kane and Dallas.
Before anyone jumps to the conclusion that my concepts are hot air, they're as fair game as the helmet being exclusive.