Wanda and Pietro being restored as Magneto’s kids shouldn’t mean Lorna loses, but there’s fair reason for the worry.
Before the forced retcon on the twins’ parentage, an editor at Marvel was absolutely adamant that Lorna “couldn’t” be Magneto’s daughter. Not only did the editor try to make up excuses, he deliberately excluded Lorna from every single thing having to do with her family. Children’s Crusade, Avengers vs X-Men, No More Humans, Axis. The editor went as far as to have a House of M picture redrawn to remove Lorna.
All this, while the editor also tried to find ways to “replace” Lorna with other characters. From having colors tweaked to make Enchantress look like Lorna on an Axis cover:
To post-Axis trying to give the twins a new “sister” that was conveniently monochrome.
To add, during Axis, the cover to All-New X-Factor #14 – where Lorna actually got to spend time with Wanda – was kept from release until the Friday before the issue would be available for purchase.
And then there’s Marvel itself. The company has a hard time showing any respect for Lorna in general. They especially don’t seem to want to acknowledge and respect her actual roots as a character, seeming to prefer how later writers ruined her by making her a lesser supporting character for Havok.
I want to stress, though, that the twins should still be restored. The family should be whole again. They have great stories together when all of them are treated with respect. Lorna only loses if a) Marvel goes through with retconning Lorna out after restoring the twins, and b) there isn’t enough pushback if Lorna gets retconned out again.
As a Lorna fan, I’m glad that she’s Magneto’s daughter. I want that explored in good ways. I want it to exist as a part of her identity, adding stories to be told, while avoiding it defining her and limiting her stories. When the whole family is together, that’s even better. My favorite family moments have been Lorna and Wanda interacting, even though most of it is only seen in AUs.
That editor who wanted Lorna not to be Magneto’s daughter, felt that way because he secretly thought it would “take away” from Wanda being “special” – another case of artificial scarcity of roles for women in comic books. Just like the “lists” of importance (A-list, B-list, Z-list, etc). It’s one of the most insidious aspects of persisting comic book attitudes from past decades.
It’s really up to fans to break those molds and push for Marvel to be better. Catering to those molds by not wanting the twins to be restored just so Lorna’s at less risk of being retconned helps nothing.